Social progress leads the development in various engineering projects. No matter the house building, boat industry or airplane construction, lots of bosses shall adopt convenient equipment for work. And thus, scaffolding products from frame scaffolding to a scaffolding base jack, should be taken safety into account.
There is safety instruction for it, and each of us need to keep in mind for safety.
First of all, before the erection of multi-pole scaffold, we should set the construction plan and the construction form shall be determined according to the plane form, size, and height and construction technology of the building.
Second, same kind of raw material for the scaffolding is necessary. Steel scaffold joints should be fastened with fasteners, not with lead wire binding.
What’s more, the pole of steel tube scaffold shall be placed vertically on the metal base, and then we should set a thick board placed below according to our installation requirement.
In addition, the adjacent joints of the vertical bar should stagger. A small bar must be set at the node of the pole. The bar at the node cannot be removed before the scaffold is removed.
Safety would be on the top list when we use scaffolding for engineering projects. Thus, be prepared for each detail is necessary.
2019年12月26日星期四
Analysis of seamless steel tube cutting problems
What should be paid attention to after the seamless steel tube is cut? What should be paid attention to during the heat treatment? The following seamless steel tube manufacturers will introduce you in detail:
1. Attention to cutting of seamless steel tube
After the seamless steel pipe is straightened, the initial inspection of soot blowing is performed to determine the length of the cut head and tail. The purpose of seamless steel tube cutting is to remove the ends with cracks, knots, scars, tears and uneven wall thickness to obtain the required fixed-size seamless steel tube. In addition, the defects that are unqualified and difficult to salvage after inspection are removed, as shown in the figure. Breaks, internal scarring, severe uneven wall thickness, etc. Generally the former is cut off on the working line, while the latter is cut off-line.
2. Control of heat preservation time during seamless steel tube heat treatment
The heat preservation time of the seamless steel tube during heat treatment should ensure that the steel pipe in the furnace can be completely burned through, make its temperature uniform, and complete the due structural transformation, so as to obtain uniform structure and performance. Generally increasing the heating temperature can shorten the holding time appropriately. When performing low temperature annealing (including softening, stress relief and recrystallization annealing),the closer the annealing temperature is to the lower critical point A1, the faster the recovery of the seamless steel pipe and the more complete the effect of eliminating work hardening, so the holding time can also be appropriately shortened.
http://www.xysteelpipe.com/info/Analysis-of-seamless-steel-tube-cutting-problems-1585-1.htm
1. Attention to cutting of seamless steel tube
After the seamless steel pipe is straightened, the initial inspection of soot blowing is performed to determine the length of the cut head and tail. The purpose of seamless steel tube cutting is to remove the ends with cracks, knots, scars, tears and uneven wall thickness to obtain the required fixed-size seamless steel tube. In addition, the defects that are unqualified and difficult to salvage after inspection are removed, as shown in the figure. Breaks, internal scarring, severe uneven wall thickness, etc. Generally the former is cut off on the working line, while the latter is cut off-line.
2. Control of heat preservation time during seamless steel tube heat treatment
The heat preservation time of the seamless steel tube during heat treatment should ensure that the steel pipe in the furnace can be completely burned through, make its temperature uniform, and complete the due structural transformation, so as to obtain uniform structure and performance. Generally increasing the heating temperature can shorten the holding time appropriately. When performing low temperature annealing (including softening, stress relief and recrystallization annealing),the closer the annealing temperature is to the lower critical point A1, the faster the recovery of the seamless steel pipe and the more complete the effect of eliminating work hardening, so the holding time can also be appropriately shortened.
http://www.xysteelpipe.com/info/Analysis-of-seamless-steel-tube-cutting-problems-1585-1.htm
2019年12月25日星期三
Three properties of 20cr seamless steel tube
(I) Chemical stability of 20cr seamless steel pipe
Refers to the general term for the corrosion resistance and oxidation resistance of 20cr seamless steel pipe materials. The chemical stability of the material at high temperatures is called thermal stability.
(II) the oxidation resistance of 20cr seamless steel pipe
The ability of 20cr seamless steel pipe to resist oxidation at room temperature or high temperature, the oxidation process is actually a form of chemical corrosion. It can directly use the amount of heavy loss after the surface of the pipe is corroded within a certain period of time, which is expressed by the speed of metal weight loss.
(III) the corrosion resistance of 20cr seamless steel pipe
The ability of a material to resist the corrosive effects of surrounding media. The corrosion resistance of metals is related to many factors, such as the chemical composition of metals, processing properties, heat treatment conditions, microstructure, and media and temperature. Chemical corrosion is the result of direct chemical interaction between metals and surrounding media. It includes two forms of gas corrosion and metal corrosion in non-electrolyte. Its characteristics are: no current is generated during the corrosion process; and corrosion products are deposited on the surface of the 20cr seamless steel pipe. To understand the corrosion resistance of 20cr seamless steel pipes, we should first grasp the following points:
(1) General corrosion: This kind of corrosion is evenly distributed on the entire inner and outer surfaces, which continuously reduces the cross-section, and finally causes the force parts to be destroyed.
(2) Pitting corrosion: The corrosion is concentrated in a small area of the surface of the 20Cr seamless steel pipe, and it develops rapidly to the deep, and finally penetrates the metal, which is a relatively harmful corrosion damage.
(3) Corrosion fatigue: refers to the damage caused by the material in the corrosive medium under the action of alternating stress.
(4) Corrosion rate: The depth of material that a metal material corrodes in a unit time is called the corrosion rate.
(5) Electrochemical corrosion: The corrosion caused by the action of 20cr seamless steel pipe when it comes into contact with electrolyte solutions such as acid, alkali and salt is called electrochemical corrosion. Its characteristic is that current is generated during the corrosion process, and its corrosion products (rust) are not covered on the metal surface as the anode, but at a certain distance from the anode metal.
(6) Intergranular corrosion: Corrosion takes place inside the metal along the edges of the grains, usually does not cause any change in the shape of the metal, and often causes sudden damage to equipment or machinery.
(7) Stress corrosion: refers to the damage caused by metals in corrosive media under the effect of static stress. The damage caused by this corrosive medium is also a type of transgranular corrosion.
(8) Corrosion rate: The weight loss of 20cr seamless steel pipe material per unit area after corrosion in a unit time is called the corrosion rate.
Refers to the general term for the corrosion resistance and oxidation resistance of 20cr seamless steel pipe materials. The chemical stability of the material at high temperatures is called thermal stability.
(II) the oxidation resistance of 20cr seamless steel pipe
The ability of 20cr seamless steel pipe to resist oxidation at room temperature or high temperature, the oxidation process is actually a form of chemical corrosion. It can directly use the amount of heavy loss after the surface of the pipe is corroded within a certain period of time, which is expressed by the speed of metal weight loss.
(III) the corrosion resistance of 20cr seamless steel pipe
The ability of a material to resist the corrosive effects of surrounding media. The corrosion resistance of metals is related to many factors, such as the chemical composition of metals, processing properties, heat treatment conditions, microstructure, and media and temperature. Chemical corrosion is the result of direct chemical interaction between metals and surrounding media. It includes two forms of gas corrosion and metal corrosion in non-electrolyte. Its characteristics are: no current is generated during the corrosion process; and corrosion products are deposited on the surface of the 20cr seamless steel pipe. To understand the corrosion resistance of 20cr seamless steel pipes, we should first grasp the following points:
(1) General corrosion: This kind of corrosion is evenly distributed on the entire inner and outer surfaces, which continuously reduces the cross-section, and finally causes the force parts to be destroyed.
(2) Pitting corrosion: The corrosion is concentrated in a small area of the surface of the 20Cr seamless steel pipe, and it develops rapidly to the deep, and finally penetrates the metal, which is a relatively harmful corrosion damage.
(3) Corrosion fatigue: refers to the damage caused by the material in the corrosive medium under the action of alternating stress.
(4) Corrosion rate: The depth of material that a metal material corrodes in a unit time is called the corrosion rate.
(5) Electrochemical corrosion: The corrosion caused by the action of 20cr seamless steel pipe when it comes into contact with electrolyte solutions such as acid, alkali and salt is called electrochemical corrosion. Its characteristic is that current is generated during the corrosion process, and its corrosion products (rust) are not covered on the metal surface as the anode, but at a certain distance from the anode metal.
(6) Intergranular corrosion: Corrosion takes place inside the metal along the edges of the grains, usually does not cause any change in the shape of the metal, and often causes sudden damage to equipment or machinery.
(7) Stress corrosion: refers to the damage caused by metals in corrosive media under the effect of static stress. The damage caused by this corrosive medium is also a type of transgranular corrosion.
(8) Corrosion rate: The weight loss of 20cr seamless steel pipe material per unit area after corrosion in a unit time is called the corrosion rate.
How to prevent rust of seamless steel tube
Choosing the right warehouse for seamless steel pipes
(1) The warehouses where seamless steel pipes are kept should be selected in a clean and well-drained place away from factories and mines that produce harmful gases or dust. Remove weeds and all debris on the site and keep steel pipes clean.
(2) Do not stack in the warehouse with materials that are corrosive to steel pipes such as acids, alkalis, salts, and cement. Different types of steel pipes should be stacked separately to prevent confusion and prevent contact corrosion.
(3) Some small steel pipes, thin steel plates, steel strips, silicon steel sheets, small-caliber or thin-walled steel pipes, various cold-rolled, cold-drawn steel pipes, and high-priced and easily corroded metal products can be stored in the warehouse.
(4) Treasury should be selected according to geographical conditions. Generally, general closed warehouses are used, that is, warehouses with roofs and walls, tight doors and windows, and ventilation facilities.
(5) Treasury requires ventilation in sunny days, and close moisture-proof in rainy days, and often maintain a suitable storage environment.
Common methods to prevent rusting of seamless steel pipes are:
(1) Composition alloy to change the internal structure of iron. For example, chromium, nickel and other metals are added to ordinary steel to make stainless steel, which greatly increases the rust resistance of steel products.
(2) Covering the surface of iron products is a common and important method to prevent iron products from rusting. According to the composition of the protective layer, it can be divided into the following types:
a. Apply mineral oil, paint or fired enamel, spray plastic on the surface of iron products. For example: cars and buckets are often painted with paint; machines are often coated with mineral oil.
b. On the surface of steel, use a method such as zinc, tin, chromium, nickel, etc. These metal surfaces can form a dense oxide film to prevent iron products from contacting water and air and rust.
c. A dense and stable oxide film is formed on the surface of iron products by chemical methods to prevent iron products from rusting.
(3) Keeping the surface of iron products clean and dry is also a good way to prevent iron products from rusting.
(1) The warehouses where seamless steel pipes are kept should be selected in a clean and well-drained place away from factories and mines that produce harmful gases or dust. Remove weeds and all debris on the site and keep steel pipes clean.
(2) Do not stack in the warehouse with materials that are corrosive to steel pipes such as acids, alkalis, salts, and cement. Different types of steel pipes should be stacked separately to prevent confusion and prevent contact corrosion.
(3) Some small steel pipes, thin steel plates, steel strips, silicon steel sheets, small-caliber or thin-walled steel pipes, various cold-rolled, cold-drawn steel pipes, and high-priced and easily corroded metal products can be stored in the warehouse.
(4) Treasury should be selected according to geographical conditions. Generally, general closed warehouses are used, that is, warehouses with roofs and walls, tight doors and windows, and ventilation facilities.
(5) Treasury requires ventilation in sunny days, and close moisture-proof in rainy days, and often maintain a suitable storage environment.
Common methods to prevent rusting of seamless steel pipes are:
(1) Composition alloy to change the internal structure of iron. For example, chromium, nickel and other metals are added to ordinary steel to make stainless steel, which greatly increases the rust resistance of steel products.
(2) Covering the surface of iron products is a common and important method to prevent iron products from rusting. According to the composition of the protective layer, it can be divided into the following types:
a. Apply mineral oil, paint or fired enamel, spray plastic on the surface of iron products. For example: cars and buckets are often painted with paint; machines are often coated with mineral oil.
b. On the surface of steel, use a method such as zinc, tin, chromium, nickel, etc. These metal surfaces can form a dense oxide film to prevent iron products from contacting water and air and rust.
c. A dense and stable oxide film is formed on the surface of iron products by chemical methods to prevent iron products from rusting.
(3) Keeping the surface of iron products clean and dry is also a good way to prevent iron products from rusting.
Method for avoiding wear of spiral steel pipe
1. Spiral steel tube packaging should prevent slackness and damage during normal loading, unloading, transportation and storage.
2. It is assumed that the purchaser has special requirements for the packaging materials and packaging methods of spiral steel pipes, which shall be specified in the contract; if not specified, the packaging materials and packaging methods shall be selected by the supplier.
3. Packaging information should conform to relevant rules. It is assumed that no packaging information is required, and it should be suitable for the intended use to prevent waste and environmental pollution.
4. Assume that the customer requires that the spiral steel pipe should not have damage such as bumps on the appearance, and can consider selecting maintenance equipment between spiral steel pipes. Maintenance equipment can use rubber, straw rope, fiber cloth, plastic, pipe caps, etc.
5, thin-wall spiral steel pipe because of the thick wall and thin can choose the method of pipe internal support or pipe maintenance. The material of the bracket and the outer frame is selected from the steel material with the spiral steel pipe material.
6, the national rules spiral steel pipe in bulk. It is assumed that customers can consider bundling as appropriate, but the caliber must be between 159MM and 500MM. The bundled materials are packed and fastened with steel belts, and each lane should be twisted into at least two strands, and added appropriately according to the outer diameter and weight of the spiral steel pipe to prevent the occurrence of looseness.
7. Fixed-length spiral steel pipes cannot be bundled.
8. If both ends of the spiral steel pipe are provided with threaded buckles, they shall be protected by thread maintainers. Apply lubricating oil or rust preventive to the threads. Spiral steel pipe is broken at both ends, and a mouthpiece protector can be added at both ends according to requirements.
9. It is assumed that when the spiral steel pipe is put into a container, the container is lined with soft, moisture-proof equipment such as textile cloth and straw mat. In order to spin the spiral steel pipe in the container, a protective support can be welded on the bundle or the outside of the spiral steel pipe.
http://www.xysteelpipe.com/info/Method-for-avoiding-wear-of-spiral-steel-pipe-1584-1.htm
2. It is assumed that the purchaser has special requirements for the packaging materials and packaging methods of spiral steel pipes, which shall be specified in the contract; if not specified, the packaging materials and packaging methods shall be selected by the supplier.
3. Packaging information should conform to relevant rules. It is assumed that no packaging information is required, and it should be suitable for the intended use to prevent waste and environmental pollution.
4. Assume that the customer requires that the spiral steel pipe should not have damage such as bumps on the appearance, and can consider selecting maintenance equipment between spiral steel pipes. Maintenance equipment can use rubber, straw rope, fiber cloth, plastic, pipe caps, etc.
5, thin-wall spiral steel pipe because of the thick wall and thin can choose the method of pipe internal support or pipe maintenance. The material of the bracket and the outer frame is selected from the steel material with the spiral steel pipe material.
6, the national rules spiral steel pipe in bulk. It is assumed that customers can consider bundling as appropriate, but the caliber must be between 159MM and 500MM. The bundled materials are packed and fastened with steel belts, and each lane should be twisted into at least two strands, and added appropriately according to the outer diameter and weight of the spiral steel pipe to prevent the occurrence of looseness.
7. Fixed-length spiral steel pipes cannot be bundled.
8. If both ends of the spiral steel pipe are provided with threaded buckles, they shall be protected by thread maintainers. Apply lubricating oil or rust preventive to the threads. Spiral steel pipe is broken at both ends, and a mouthpiece protector can be added at both ends according to requirements.
9. It is assumed that when the spiral steel pipe is put into a container, the container is lined with soft, moisture-proof equipment such as textile cloth and straw mat. In order to spin the spiral steel pipe in the container, a protective support can be welded on the bundle or the outside of the spiral steel pipe.
http://www.xysteelpipe.com/info/Method-for-avoiding-wear-of-spiral-steel-pipe-1584-1.htm
2019年12月15日星期日
Carbon Steel Alloy-ASTM A53
ASTM A53 is a carbon steel alloy,used as structural steel or for low-pressure plumbing.The alloy specifications are set by ASTM international,in specifications ASTM A53/A53M.
A53 pipe comes in three types and two grades,A53 Type F,which is longitudinally furnace butt welded or continuous welded(Grade A only),A53 Type E，which is longitudinally electric resistance welded(Grades A and B)，and A53 Type S,which is seamless pipe,produced by hot working,and possibly cold finishing,the steel(Grade A and B).ASTM A53 pipe is sized according to the nominal pipe size(NPS)system.It is commonly available with national pipe thread ends or with plain cut ends.It can be used for steam,water,and air conveyance.It is also weldable and can be used in structural application,although ASTM A500 tube,which is available in the same NPS
Sizes,is sometime preferred.
This is a standard set by the standards organization ASTM international,a voluntary standards development organizations that sets technical standards for materials,products,systems,and service.
A53 pipe comes in three types and two grades,A53 Type F,which is longitudinally furnace butt welded or continuous welded(Grade A only),A53 Type E，which is longitudinally electric resistance welded(Grades A and B)，and A53 Type S,which is seamless pipe,produced by hot working,and possibly cold finishing,the steel(Grade A and B).ASTM A53 pipe is sized according to the nominal pipe size(NPS)system.It is commonly available with national pipe thread ends or with plain cut ends.It can be used for steam,water,and air conveyance.It is also weldable and can be used in structural application,although ASTM A500 tube,which is available in the same NPS
Sizes,is sometime preferred.
This is a standard set by the standards organization ASTM international,a voluntary standards development organizations that sets technical standards for materials,products,systems,and service.
Why do stainless steel fittings need solution treatment?
Austenitic stainless steel is softened by solution treatment. Generally, the stainless steel pipe is heated to about 950 to 1150 ° C for a period of time, so that carbides and various alloy elements are completely and uniformly dissolved in austenite, and then quenched and cooled quickly. Carbon and other alloying elements are too late to precipitate and a pure austenite structure is obtained, which is called a solution treatment.
Solution treatment has three effects.
1. Due to the different rolling temperature and cooling rate of each section of the hot-rolled wire rod, the structure is inconsistent. Therefore, it is particularly important for the raw materials to make the structure and composition of the stainless steel pipe uniform.
At high temperatures, the atomic activity is enhanced, the polymer phase is dissolved, and the chemical composition tends to be uniform. After cooling, a uniform single-phase structure is obtained.
2. Eliminate work hardening to promote continuous cold work.
After the solution treatment, the deformed crystal lattice is restored, the elongated and fractured grains are recrystallized, the internal stress is eliminated, the tensile strength of the stainless steel pipe is reduced, and the elongation is increased.
3. Repair the inherent corrosion resistance of stainless steel pipe fittings.
Due to carbide precipitation caused by cold working, lattice defects lead to reduced corrosion resistance of stainless steel pipe fittings. After solution treatment, the corrosion resistance of stainless steel pipe fittings is restored to a better state.
The three elements of solution treatment of stainless steel pipe fittings are temperature, holding time and cooling rate. The solution temperature is mainly determined by the chemical composition.
In general, for grades with multiple alloying elements and high contents, the solution temperature should be increased accordingly. In particular, steels with high Mn, Mo, Ni, and Si content can only be softened by increasing the solution temperature and sufficiently dissolving.
However, in stable steels such as 1Cr18Ni9Ti, when the solid solution temperature is high, the carbides of the stabilizing element are sufficiently dissolved in austenite, and then precipitated at the grain boundaries in the form of Cr23C6 during subsequent cooling, causing intergranular corrosion.
In order to prevent decomposition or solid solution of the carbides (TiC and Nbc) of the stabilizing element, a lower limit solid solution temperature is usually used.
As the saying goes, stainless steel pipe is not easy to rust. In fact, part of the stainless steel pipe contains both stainless steel and acid resistance (corrosion resistance). The rust and corrosion resistance of stainless steel pipe fittings is caused by the formation of a chromium-rich oxide film (passivation film) on the surface. Stainless steel tubing and corrosion resistance are relative.
The experimental results show that the corrosion resistance of steel in weak media such as atmosphere and water and the oxidation medium such as nitric acid will increase with the increase of chromium water content in steel, and it is proportional to the corrosion resistance of stainless steel pipe fittings.
When the chromium content reaches a certain percentage, the corrosion resistance of stainless steel pipe fittings changes suddenly, that is, from rust to non-rust, and from corrosion to corrosion resistance.
Solution treatment has three effects.
1. Due to the different rolling temperature and cooling rate of each section of the hot-rolled wire rod, the structure is inconsistent. Therefore, it is particularly important for the raw materials to make the structure and composition of the stainless steel pipe uniform.
At high temperatures, the atomic activity is enhanced, the polymer phase is dissolved, and the chemical composition tends to be uniform. After cooling, a uniform single-phase structure is obtained.
2. Eliminate work hardening to promote continuous cold work.
After the solution treatment, the deformed crystal lattice is restored, the elongated and fractured grains are recrystallized, the internal stress is eliminated, the tensile strength of the stainless steel pipe is reduced, and the elongation is increased.
3. Repair the inherent corrosion resistance of stainless steel pipe fittings.
Due to carbide precipitation caused by cold working, lattice defects lead to reduced corrosion resistance of stainless steel pipe fittings. After solution treatment, the corrosion resistance of stainless steel pipe fittings is restored to a better state.
The three elements of solution treatment of stainless steel pipe fittings are temperature, holding time and cooling rate. The solution temperature is mainly determined by the chemical composition.
In general, for grades with multiple alloying elements and high contents, the solution temperature should be increased accordingly. In particular, steels with high Mn, Mo, Ni, and Si content can only be softened by increasing the solution temperature and sufficiently dissolving.
However, in stable steels such as 1Cr18Ni9Ti, when the solid solution temperature is high, the carbides of the stabilizing element are sufficiently dissolved in austenite, and then precipitated at the grain boundaries in the form of Cr23C6 during subsequent cooling, causing intergranular corrosion.
In order to prevent decomposition or solid solution of the carbides (TiC and Nbc) of the stabilizing element, a lower limit solid solution temperature is usually used.
As the saying goes, stainless steel pipe is not easy to rust. In fact, part of the stainless steel pipe contains both stainless steel and acid resistance (corrosion resistance). The rust and corrosion resistance of stainless steel pipe fittings is caused by the formation of a chromium-rich oxide film (passivation film) on the surface. Stainless steel tubing and corrosion resistance are relative.
The experimental results show that the corrosion resistance of steel in weak media such as atmosphere and water and the oxidation medium such as nitric acid will increase with the increase of chromium water content in steel, and it is proportional to the corrosion resistance of stainless steel pipe fittings.
When the chromium content reaches a certain percentage, the corrosion resistance of stainless steel pipe fittings changes suddenly, that is, from rust to non-rust, and from corrosion to corrosion resistance.
Advantages of natural gas 3pe anticorrosive steel pipe
Natural gas 3pe anti-corrosion steel pipe This three-layer coating system combines the excellent properties of single-layer epoxy and polyethylene coatings. Natural gas 3pe anti-corrosion steel pipe meets the requirements of operating temperature (90 ° C) and improves the resistance of the coating system. Cathode peeling and adhesion strength, three-layer structure polyethylene anticorrosive coating has excellent mechanical protection and adhesion properties.
It can withstand the stress caused by the movement of the soil caused by vibration and temperature changes, and can resist the impact stress of sharp stones on the pipe surface. The resistance of the water supply polyethylene anticorrosive coating in the community is high, which will greatly reduce the installation and maintenance costs of the cathodic protection system. The current density of the cathodic protection of the three-layer structure polyethylene anticorrosive coating pipeline is less than 10 μA * m2.
Epoxy resin powder has high adhesion, peeling properties, chemical barrier properties and oxygen resistance. The polymer coating and the epoxy resin bottom layer have good chemical adhesion, and the natural gas 3PE anticorrosive steel pipe can resist the shear force caused by soil movement and temperature change. High-density poly surface coating has a good barrier effect against moisture, can protect the epoxy resin bottom layer and polymer coating, has strong resistance to mechanical damage, peeling, and low cathodic protection current, and has a wide temperature range (from 5 to 0 8 zero ° C).
The combination of three-layer structure polyethylene anticorrosive coating is characterized by the combination and enhancement of the three coatings. The three-layer coating has strong chemical adhesion. The performance and characteristics of each layer make the three-layer coating complement each other. This three-layer anti-corrosion coating is integrated into a three-in-one form, and makes the overall chemical and mechanical properties reach a good degree. It combines the good adhesion properties of epoxy resin, chemical resistance and mechanical properties of polyethylene coating Strength and protection.
Natural gas 3pe anti-corrosion steel pipe is widely used in anti-corrosion projects of metal pipelines such as gas, oil, and water. Steel pipe is preheated. The steel pipe treated with fine dust should be preheated before epoxy powder coating. The natural gas 3pe anticorrosive steel pipe is heated by a KGPS-750uw constant power intermediate frequency machine. The preheating temperature must meet the requirements of the environment. The temperature required for oxygen powder coatings, but the maximum temperature must not exceed 275 ° C.
It can withstand the stress caused by the movement of the soil caused by vibration and temperature changes, and can resist the impact stress of sharp stones on the pipe surface. The resistance of the water supply polyethylene anticorrosive coating in the community is high, which will greatly reduce the installation and maintenance costs of the cathodic protection system. The current density of the cathodic protection of the three-layer structure polyethylene anticorrosive coating pipeline is less than 10 μA * m2.
Epoxy resin powder has high adhesion, peeling properties, chemical barrier properties and oxygen resistance. The polymer coating and the epoxy resin bottom layer have good chemical adhesion, and the natural gas 3PE anticorrosive steel pipe can resist the shear force caused by soil movement and temperature change. High-density poly surface coating has a good barrier effect against moisture, can protect the epoxy resin bottom layer and polymer coating, has strong resistance to mechanical damage, peeling, and low cathodic protection current, and has a wide temperature range (from 5 to 0 8 zero ° C).
The combination of three-layer structure polyethylene anticorrosive coating is characterized by the combination and enhancement of the three coatings. The three-layer coating has strong chemical adhesion. The performance and characteristics of each layer make the three-layer coating complement each other. This three-layer anti-corrosion coating is integrated into a three-in-one form, and makes the overall chemical and mechanical properties reach a good degree. It combines the good adhesion properties of epoxy resin, chemical resistance and mechanical properties of polyethylene coating Strength and protection.
Natural gas 3pe anti-corrosion steel pipe is widely used in anti-corrosion projects of metal pipelines such as gas, oil, and water. Steel pipe is preheated. The steel pipe treated with fine dust should be preheated before epoxy powder coating. The natural gas 3pe anticorrosive steel pipe is heated by a KGPS-750uw constant power intermediate frequency machine. The preheating temperature must meet the requirements of the environment. The temperature required for oxygen powder coatings, but the maximum temperature must not exceed 275 ° C.
Several methods of connection of anticorrosive steel pipe are introduced
Generally speaking, because the cost of anticorrosive steel pipes is relatively low, the connection method of anticorrosive spiral steel pipes is welding. Due to the limitation of construction period, construction conditions, geographical environment and other factors, some projects will also use other connection methods, such as screw connection, flange connection, socket connection, slot connection and so on.
1. Flange connection anticorrosive steel pipe generally has the advantages of fast speed, convenient construction, simple tools, etc., but it cannot meet most engineering requirements in terms of safety and tightness. Generally, low-pressure pipes are suitable for this connection, such as sludge pipes.
2. Grooved anticorrosive steel pipe: Also known as clamp connection technology, it has become the first technology to connect liquid and gas pipelines. Although this technology developed later in China than abroad, it was quickly accepted by the domestic market due to its advanced technology. The application of grooved pipe connection technology makes the complicated pipe connection process simple, fast and convenient. Pipe connection technology is a big step forward. Grooved connectors include two products:
1) rigid joints, flexible joints, mechanical tees and grooved flanges;
2) Elbows, tees, crosses, reducers, blind plates, spiral welded pipes, etc. The grooved connecting pipe fittings for connection and sealing are mainly composed of three parts: a sealing rubber ring, a clamp and a locking bolt. The rubber seal ring on the inner layer is placed outside the connecting pipe and coincides with the pre-rolling groove. Then tighten the clamp on the outside of the rubber ring, and then tighten with two bolts. Due to the special sealing structure design of the rubber sealing ring and the clamp, the groove connection has a good sealing performance. As the fluid pressure in the pipeline increases, its sealing performance also improves accordingly.
The trench connection makes the pipeline connection easy to operate, conducive to construction safety, good system stability, convenient maintenance, saving time and labor, and good economic benefits. When using a clamp connection, although the price of a single piece of the clamp is higher, the overall benefit of the entire pipe network installation is higher than the flange connection.
3. As a kind of advanced anti-corrosion steel pipe connection method, the clamp pipe fittings can be exposed or concealed, that is, steel joints or flexible joints. Therefore, it has broad application prospects. Suitable for firefighting water supply system, air-conditioning hot and cold water system, water supply system, petrochemical pipeline system, thermoelectric military pipeline system, sewage treatment pipeline system, etc.
1. Flange connection anticorrosive steel pipe generally has the advantages of fast speed, convenient construction, simple tools, etc., but it cannot meet most engineering requirements in terms of safety and tightness. Generally, low-pressure pipes are suitable for this connection, such as sludge pipes.
2. Grooved anticorrosive steel pipe: Also known as clamp connection technology, it has become the first technology to connect liquid and gas pipelines. Although this technology developed later in China than abroad, it was quickly accepted by the domestic market due to its advanced technology. The application of grooved pipe connection technology makes the complicated pipe connection process simple, fast and convenient. Pipe connection technology is a big step forward. Grooved connectors include two products:
1) rigid joints, flexible joints, mechanical tees and grooved flanges;
2) Elbows, tees, crosses, reducers, blind plates, spiral welded pipes, etc. The grooved connecting pipe fittings for connection and sealing are mainly composed of three parts: a sealing rubber ring, a clamp and a locking bolt. The rubber seal ring on the inner layer is placed outside the connecting pipe and coincides with the pre-rolling groove. Then tighten the clamp on the outside of the rubber ring, and then tighten with two bolts. Due to the special sealing structure design of the rubber sealing ring and the clamp, the groove connection has a good sealing performance. As the fluid pressure in the pipeline increases, its sealing performance also improves accordingly.
The trench connection makes the pipeline connection easy to operate, conducive to construction safety, good system stability, convenient maintenance, saving time and labor, and good economic benefits. When using a clamp connection, although the price of a single piece of the clamp is higher, the overall benefit of the entire pipe network installation is higher than the flange connection.
3. As a kind of advanced anti-corrosion steel pipe connection method, the clamp pipe fittings can be exposed or concealed, that is, steel joints or flexible joints. Therefore, it has broad application prospects. Suitable for firefighting water supply system, air-conditioning hot and cold water system, water supply system, petrochemical pipeline system, thermoelectric military pipeline system, sewage treatment pipeline system, etc.
2019年12月12日星期四
What are the factors that affect the performance of large flanges?
Annealing temperature (annealing temperature is the temperature parameter when the primer and template are separated. When 50% of the primers and complementary sequences are double-stranded DNA molecules, the annealing temperature is an important factor affecting the specificity of PCR.
Ideally, the annealing temperature is low enough to ensure efficient annealing of homologous primers, and high enough to reduce non-specific separations. A reasonable annealing temperature range is 55 to 70 ° C. The annealing temperature is generally 5 ° C lower than the primer TM.
Can we reach normal temperature? Large flanges generally adopt solution heat treatment, commonly known as "annealing", and the temperature range is 1040 ~ 1120 ℃. You can also check the annealing furnace and find that the large flange fittings in the annealing zone should be incandescent, but not soften and sag.
Secondly, the tightness of the furnace body (furnace shell is welded by steel plate and section steel, and trolley is welded by steel section and steel plate). Through the soft contact sand sealing mechanism with the furnace lining, the trolley can reduce heat radiation and convection loss, and effectively ensure the tightness of the furnace body. The bright annealing furnace should be closed and isolated from the outside air. As long as an exhaust port is opened (for igniting the discharged hydrogen), the hydrogen is used as a maintenance gas. This inspection method can clean the gaps between the joints of the annealing furnace with soapy water to see if it can run away. The easiest outflow center is the center of the inlet and outlet tubes of the annealing furnace. This type of central seal is particularly prone to wear and should be inspected and replaced frequently.
Secondly, maintenance pressure, in order to avoid slight leakage, the furnace maintenance gas should adhere to a certain positive pressure, if it is hydrogen maintenance gas, generally requires more than 20kbar. Annealing atmosphere: Generally, pure hydrogen is used as the annealing atmosphere, and the purity of the atmosphere is greater than 99.99%. If the other part of the atmosphere is an inert gas, the purity can be reduced, but it must not contain excessive oxygen and water vapor.
Ideally, the annealing temperature is low enough to ensure efficient annealing of homologous primers, and high enough to reduce non-specific separations. A reasonable annealing temperature range is 55 to 70 ° C. The annealing temperature is generally 5 ° C lower than the primer TM.
Can we reach normal temperature? Large flanges generally adopt solution heat treatment, commonly known as "annealing", and the temperature range is 1040 ~ 1120 ℃. You can also check the annealing furnace and find that the large flange fittings in the annealing zone should be incandescent, but not soften and sag.
Secondly, the tightness of the furnace body (furnace shell is welded by steel plate and section steel, and trolley is welded by steel section and steel plate). Through the soft contact sand sealing mechanism with the furnace lining, the trolley can reduce heat radiation and convection loss, and effectively ensure the tightness of the furnace body. The bright annealing furnace should be closed and isolated from the outside air. As long as an exhaust port is opened (for igniting the discharged hydrogen), the hydrogen is used as a maintenance gas. This inspection method can clean the gaps between the joints of the annealing furnace with soapy water to see if it can run away. The easiest outflow center is the center of the inlet and outlet tubes of the annealing furnace. This type of central seal is particularly prone to wear and should be inspected and replaced frequently.
Secondly, maintenance pressure, in order to avoid slight leakage, the furnace maintenance gas should adhere to a certain positive pressure, if it is hydrogen maintenance gas, generally requires more than 20kbar. Annealing atmosphere: Generally, pure hydrogen is used as the annealing atmosphere, and the purity of the atmosphere is greater than 99.99%. If the other part of the atmosphere is an inert gas, the purity can be reduced, but it must not contain excessive oxygen and water vapor.
2019年12月2日星期一
Boiler tube formation
Boiler pipe forming: ① fin tube ② serpentine tube ③ reaming welding
Industrial boilers occupy a very important position in the modern energy industry, is a major industrial power or production equipment. In order to improve the thermal efficiency of the boiler, using a steel pipe manufacturing boilers, increasing heating area. Thus, in the medium and low pressure boiler or high pressure boiler works, boiler pipe accounts for a great part, about 30% to 60% of boiler steel, used as boiler engineering stave pipes, economizer tubes, heat exchanger tubes convection tubes, superheater tubes, etc., used in locomotive boiler opium pipe, small pipe and so on.
Boiler tubes need take for a variety of molding in the boiler manufacture and installation process ; for example stave pipe in pipe welding corresponding sides made of slats or finned-tube, also known as "fin tubes." The tube heat exchanger tubes often need to be processed into a certain shape, like snake collectively "serpentine"; welding locomotive boiler header tubes, both ends need to be processed after reaming. Therefore, in order to detect boiler tube pipe processing technology performance, except for routine physical and chemical properties of the test, but still need to make the appropriate technology test.
The purpose of the test is to detect plasticity situation of boiler pipes in the process. Process test generally includes: upset test, bending test, necking test, flaring test, curling test and flattening test and so on.
Industrial boilers occupy a very important position in the modern energy industry, is a major industrial power or production equipment. In order to improve the thermal efficiency of the boiler, using a steel pipe manufacturing boilers, increasing heating area. Thus, in the medium and low pressure boiler or high pressure boiler works, boiler pipe accounts for a great part, about 30% to 60% of boiler steel, used as boiler engineering stave pipes, economizer tubes, heat exchanger tubes convection tubes, superheater tubes, etc., used in locomotive boiler opium pipe, small pipe and so on.
Boiler tubes need take for a variety of molding in the boiler manufacture and installation process ; for example stave pipe in pipe welding corresponding sides made of slats or finned-tube, also known as "fin tubes." The tube heat exchanger tubes often need to be processed into a certain shape, like snake collectively "serpentine"; welding locomotive boiler header tubes, both ends need to be processed after reaming. Therefore, in order to detect boiler tube pipe processing technology performance, except for routine physical and chemical properties of the test, but still need to make the appropriate technology test.
The purpose of the test is to detect plasticity situation of boiler pipes in the process. Process test generally includes: upset test, bending test, necking test, flaring test, curling test and flattening test and so on.
The difference between carbon steel and alloy steel
Carbon steel is also known as the iron-carbon alloy containing less than 2% carbon WC. Generally also contain small amounts of silicon, manganese, sulfur, phosphorus and carbon steel, in addition to carbon use can be divided into carbon steel and carbon structural steel, carbon tool steel, and ease of cutting structural steel three categories. Carbon structural steel is divided into building structural steel and machinery manufacturing structural steel two kinds. According to the carbon steel, carbon content can be divided into low-carbon steel (WC ≤ 0.25%), medium carbon steel (WC0.25% - 0.6%) phosphorus, sulfur content and high-carbon steel (WC> 6%) can be divided into ordinary carbon steel (containing phosphorus, sulfur higher), high-quality carbon steel (containing phosphorus, low sulfur) and high quality steel (phosphorus, sulfur less), generally, the higher carbon content, the higher the hardness, higher strength but lower ductility.
Alloy steel refers to steel in addition to silicon and manganese as an alloying element or a deoxidizing element, but also contain other alloying elements (such as chromium, nickel, molybdenum, vanadium, titanium, copper, tungsten, aluminum, cobalt, niobium, zirconium, and other elementsetc.), and some also contain certain non-metallic elements (such as boron, nitrogen, etc.) of the steel. How much of the content of alloying elements in steel, can be divided into low-alloy steel, alloy steel and high-alloy steel.
Alloy steel refers to steel in addition to silicon and manganese as an alloying element or a deoxidizing element, but also contain other alloying elements (such as chromium, nickel, molybdenum, vanadium, titanium, copper, tungsten, aluminum, cobalt, niobium, zirconium, and other elementsetc.), and some also contain certain non-metallic elements (such as boron, nitrogen, etc.) of the steel. How much of the content of alloying elements in steel, can be divided into low-alloy steel, alloy steel and high-alloy steel.
Cold drawn steel pipe is passivated by pickling
The appearance of the cold drawn steel pipe will form a dense oxide film, to prevent the concentrated sulfuric acid or nitric acid to further react with the phenomenon called passivation. An active metal or an alloy, wherein the chemical activity is greatly reduced, and a noble metal state phenomenon, called passivation.
Metal generated by the role of the medium due to corrosion products, which has a dense structure, the formation of a layer of film (often invisible tightly covered in the outer of the metal, then change the state of the metal on the outer significantly to the positive direction, so that the electrode potential of the metal transitions become passive corrosion such as FeFe + + when the specification potential transition to +0.51 V-0.44V passivation shows precious metals corrosion performance, this film is called passivation film cold drawn steel pipe chromate solution with Miles hung metal appearance generated trivalent or hexavalent chromium layer, called passivation, Yiming chromium used for the disposal of aluminum, magnesium and their alloys can also form on the steel chromium layer, but rarely used alone, often phosphide and supporting the use of, to close the porosity of the phosphate layer, the phosphating layer bare steel passivation, to inhibit the corrosive effect of the remaining phosphating accelerator, to further increase the protective capacity cold drawn steel pipe passivation Usually using potassium dichromate solution (2 to 4 grams / liter, and sometimes 1 to 2 g of phosphoric acid was added) 80-90 degrees Celsius dip Tut 2-3 minutes to remove.
Metal generated by the role of the medium due to corrosion products, which has a dense structure, the formation of a layer of film (often invisible tightly covered in the outer of the metal, then change the state of the metal on the outer significantly to the positive direction, so that the electrode potential of the metal transitions become passive corrosion such as FeFe + + when the specification potential transition to +0.51 V-0.44V passivation shows precious metals corrosion performance, this film is called passivation film cold drawn steel pipe chromate solution with Miles hung metal appearance generated trivalent or hexavalent chromium layer, called passivation, Yiming chromium used for the disposal of aluminum, magnesium and their alloys can also form on the steel chromium layer, but rarely used alone, often phosphide and supporting the use of, to close the porosity of the phosphate layer, the phosphating layer bare steel passivation, to inhibit the corrosive effect of the remaining phosphating accelerator, to further increase the protective capacity cold drawn steel pipe passivation Usually using potassium dichromate solution (2 to 4 grams / liter, and sometimes 1 to 2 g of phosphoric acid was added) 80-90 degrees Celsius dip Tut 2-3 minutes to remove.
Annealing process of seamless steel tube
Annealing process of seamless steel pipe:
1. Fully annealed. It is used to refine the coarse and superheated structure with poor mechanical properties in medium and low carbon steels after casting, forging and welding. The workpiece is heated to a temperature between 30 and 50 ° C above the temperature at which ferrite is completely transformed into austenite, and is held for a period of time, and then slowly cooled with the furnace. During the cooling process, the austenite is transformed again, which can make the steel structure fine .
2. Spheroidizing annealing. Used to reduce the high hardness of tool steel and bearing steel after forging. The workpiece is heated to a temperature between 20 and 40 ° C above the temperature at which the steel begins to form austenite, and is slowly cooled after the heat preservation. During the cooling process, the lamellar cementite in pearlite becomes spherical, thereby reducing the hardness.
3. Isothermal annealing. Used to reduce the high hardness of some alloy structural steels with higher nickel and chromium content for cutting. Generally, it is first cooled to the most unstable temperature of austenite at a relatively rapid rate, and after holding for an appropriate time, the austenite is transformed into toustenite or sorbite, and the hardness can be reduced.
4. Recrystallization annealing. It is used to eliminate the hardening phenomenon (increased hardness and decreased plasticity) of metal wires and sheets during cold drawing and cold rolling. The heating temperature is generally 50 to 150 ° C below the temperature at which the steel begins to form austenite. Only in this way can the work hardening effect be softened.
5. Graphitizing annealing. Used to make cast iron containing a large amount of cementite into malleable cast iron with good plasticity. The technical operation is to heat the casting to about 950 ° C, and then cool it properly after holding for a certain period of time to decompose the cementite to form flocculent graphite.
6. Diffusion annealing. Used to homogenize the chemical composition of alloy castings and improve their performance. The method is to heat the casting to the highest possible temperature without melting, and keep it warm for a long time, and then slowly cool after the various elements in the alloy tend to be uniformly distributed.
7. Stress relief annealing. Used to eliminate the internal stress of steel castings and weldments.
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1. Fully annealed. It is used to refine the coarse and superheated structure with poor mechanical properties in medium and low carbon steels after casting, forging and welding. The workpiece is heated to a temperature between 30 and 50 ° C above the temperature at which ferrite is completely transformed into austenite, and is held for a period of time, and then slowly cooled with the furnace. During the cooling process, the austenite is transformed again, which can make the steel structure fine .
2. Spheroidizing annealing. Used to reduce the high hardness of tool steel and bearing steel after forging. The workpiece is heated to a temperature between 20 and 40 ° C above the temperature at which the steel begins to form austenite, and is slowly cooled after the heat preservation. During the cooling process, the lamellar cementite in pearlite becomes spherical, thereby reducing the hardness.
3. Isothermal annealing. Used to reduce the high hardness of some alloy structural steels with higher nickel and chromium content for cutting. Generally, it is first cooled to the most unstable temperature of austenite at a relatively rapid rate, and after holding for an appropriate time, the austenite is transformed into toustenite or sorbite, and the hardness can be reduced.
4. Recrystallization annealing. It is used to eliminate the hardening phenomenon (increased hardness and decreased plasticity) of metal wires and sheets during cold drawing and cold rolling. The heating temperature is generally 50 to 150 ° C below the temperature at which the steel begins to form austenite. Only in this way can the work hardening effect be softened.
5. Graphitizing annealing. Used to make cast iron containing a large amount of cementite into malleable cast iron with good plasticity. The technical operation is to heat the casting to about 950 ° C, and then cool it properly after holding for a certain period of time to decompose the cementite to form flocculent graphite.
6. Diffusion annealing. Used to homogenize the chemical composition of alloy castings and improve their performance. The method is to heat the casting to the highest possible temperature without melting, and keep it warm for a long time, and then slowly cool after the various elements in the alloy tend to be uniformly distributed.
7. Stress relief annealing. Used to eliminate the internal stress of steel castings and weldments.
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Galvanized steel pipe welding
The galvanized steel pipe is characterized by its excellent benefits such as corrosion resistance, long life, low initial cost and maintenance costs, has been wieldy used in outdoor and indoor, marine and underground applications
Galvanized steel pipe is a 20um thick zinc coating on the outside of the low carbon steel pipe. The melting point of zinc is at 419°C and the boiling point is around 908° ℃. In welding, zinc is melted on the surface of the molten pool or at the root of the weld. Since zinc has a relatively high solid solubility in iron, the zinc liquid will deeply erode the weld metal along the grain boundary, forming "liquid metal embrittlement". At the same time, zinc and iron can form an intermetallic brittle compound, which reduces the plasticity of the weld metal and leads to cracks under the action of tensile stress.
When welding galvanized steel, the surface of groove and the edge of the zinc layer under the action of arc heat, oxidation, melting and evaporation of white smoke and steam easily lead to weld porosity. ZnO formed by oxidation has a high melting point, above 1800°C. If the parameters are too small in the welding process, ZnO slag inclusion will be caused. Meanwhile, as Zn becomes a deoxidizer, FeO-MnO or Feo-Mno-Sio2 oxide slag inclusion with low melting point will be generated. It must be noted that the white dust of zinc volatilization is harmful to human body and the galvanized layer at welding must be polished off.
Step 1: Polishing
The galvanized layer must be polished off at the welding part, otherwise will occur bubbles, trachoma, false welding and other defects, which leads to brittle welding seam and rigidity decreases.
Step 2: Weld groove
The preparation of galvanized steel before welding is similar to the general low carbon steel, it is necessary to pay attention to the groove size and galvanized layer. The groove size is generally 60~65° and there is a certain gap, generally 1.5~2.5mm; In order to reduce the penetration of zinc into the weld, the galvanized layer in the groove can be removed before welding and then welded. In practical welding, the groove is generally concentrated and no blunt edge is left. Two-layer welding reduces the possibility of incomplete welding. The welding rod should be selected according to the base material of galvanized steel tube. Generally speaking, J422 is an ideal choice.
Step 3: Welding
In the first layer of multilayer welding weld, try to melt the zinc layer and make it vaporized, evaporation, this can greatly reduce the zinc liquid remained in the weld. The same method is used for fillet welds. First move the electrode tail forward about 5~7mm, and then return to the original position to continue welding after melting the zinc layer. If the choice of short slag electrode such as J427, there will be a very small bite edge tendency; Back and forth input electrode can get the welding quality without defects.
Galvanized steel pipe is a 20um thick zinc coating on the outside of the low carbon steel pipe. The melting point of zinc is at 419°C and the boiling point is around 908° ℃. In welding, zinc is melted on the surface of the molten pool or at the root of the weld. Since zinc has a relatively high solid solubility in iron, the zinc liquid will deeply erode the weld metal along the grain boundary, forming "liquid metal embrittlement". At the same time, zinc and iron can form an intermetallic brittle compound, which reduces the plasticity of the weld metal and leads to cracks under the action of tensile stress.
When welding galvanized steel, the surface of groove and the edge of the zinc layer under the action of arc heat, oxidation, melting and evaporation of white smoke and steam easily lead to weld porosity. ZnO formed by oxidation has a high melting point, above 1800°C. If the parameters are too small in the welding process, ZnO slag inclusion will be caused. Meanwhile, as Zn becomes a deoxidizer, FeO-MnO or Feo-Mno-Sio2 oxide slag inclusion with low melting point will be generated. It must be noted that the white dust of zinc volatilization is harmful to human body and the galvanized layer at welding must be polished off.
Step 1: Polishing
The galvanized layer must be polished off at the welding part, otherwise will occur bubbles, trachoma, false welding and other defects, which leads to brittle welding seam and rigidity decreases.
Step 2: Weld groove
The preparation of galvanized steel before welding is similar to the general low carbon steel, it is necessary to pay attention to the groove size and galvanized layer. The groove size is generally 60~65° and there is a certain gap, generally 1.5~2.5mm; In order to reduce the penetration of zinc into the weld, the galvanized layer in the groove can be removed before welding and then welded. In practical welding, the groove is generally concentrated and no blunt edge is left. Two-layer welding reduces the possibility of incomplete welding. The welding rod should be selected according to the base material of galvanized steel tube. Generally speaking, J422 is an ideal choice.
Step 3: Welding
In the first layer of multilayer welding weld, try to melt the zinc layer and make it vaporized, evaporation, this can greatly reduce the zinc liquid remained in the weld. The same method is used for fillet welds. First move the electrode tail forward about 5~7mm, and then return to the original position to continue welding after melting the zinc layer. If the choice of short slag electrode such as J427, there will be a very small bite edge tendency; Back and forth input electrode can get the welding quality without defects.
2019年11月20日星期三
What is the ladder buckle oil casing
Because the yoke buckle oil casing is shaped like a ladder, it is called a stepped oil casing pipe, which is one of the commonly used buckle shapes for oil casings.
The ladder ladder oil casing is abbreviated as btc ladder ladder oil casing. It is mainly used for supporting the well wall during and after drilling to ensure the drilling process and the normal operation of the entire well after completion. The casing of the casing offset buckle oil casing is bundled with steel wire or steel belt.
According to different well conditions and different depths of geological conditions, different grades of ladder-type oil casings are selected. The casing itself is also required to have corrosion resistance in a corrosive environment. The formula for calculating the weight is: [(outer diameter - wall thickness) * wall thickness] * 0.02466 = kg / m (weight per meter), the main materials include J55, K55, N80, L80, C90, T95, P110, Q125, V150. The advantages of the trapezoidal thread profile increase the resistance to axial and axial compression loads and provide leakage resistance.
http://www.xysteelpipe.com/info/What-is-the-ladder-buckle-oil-casing-1557-1.htm
The ladder ladder oil casing is abbreviated as btc ladder ladder oil casing. It is mainly used for supporting the well wall during and after drilling to ensure the drilling process and the normal operation of the entire well after completion. The casing of the casing offset buckle oil casing is bundled with steel wire or steel belt.
According to different well conditions and different depths of geological conditions, different grades of ladder-type oil casings are selected. The casing itself is also required to have corrosion resistance in a corrosive environment. The formula for calculating the weight is: [(outer diameter - wall thickness) * wall thickness] * 0.02466 = kg / m (weight per meter), the main materials include J55, K55, N80, L80, C90, T95, P110, Q125, V150. The advantages of the trapezoidal thread profile increase the resistance to axial and axial compression loads and provide leakage resistance.
http://www.xysteelpipe.com/info/What-is-the-ladder-buckle-oil-casing-1557-1.htm
2019年11月19日星期二
Ultrasonic inspection of thin wall tubing
Ultrasonic inspection of thin wall tubing is as follows:
(1) Detection method. Ultrasonic inspection of thin wall tubing is mainly carried out by automatic detection. The forms are:
① The probe is fixed, and the steel pipe is spirally advanced by the mechanical transmission device, so that the probe moves relative to the axis of the pipe. A single-wafer water immersion line focusing probe and a single-channel A-type pulse reflection ultrasonic flaw detector are usually used to detect the longitudinal (distribution along the axis of the tube) defects in the inner and outer walls of the tube.
② The pipe is rotated by the mechanical transmission equipment. The probe is driven by the drive trolley to move at a uniform speed along the axis of the pipe. The probes, instruments and detection defects used are the same as ①.
③ While the probe is rotating, the pipe is fed straight by the mechanical transmission equipment. Generally, multiple probes with different functions and different forms are used. The multi-channel ultrasonic flaw detector is used to simultaneously detect the longitudinal, lateral and layer defects of the inner and outer walls of the pipe. At the same time, the wall thickness of the tube is measured and the ellipticity is checked.
The detection method has a high degree of automation, and can simultaneously detect multi-directional defects, and can be combined with a micro-processor or an automatic multi-recorder for automatic print recording, quality sorting and the like.
(2) Detection frequency. Due to the thin wall thickness of the tube and the small size for effective pairing. The defects are detected and generally use a frequency of 5 MHz or higher.
(3) Acoustic coupling.
Regardless of the detection method used, water-treated water is used as a coupling agent in the ultrasonic testing of small-diameter thin-walled tubes. The basic requirement is to ensure that the water is sufficiently wetted on the surface of the steel pipe without generating blisters and reducing the corrosion of water on the steel pipe material.
(4) Acoustic wave incident angle adjustment.
① Horizontal offset method: the axis of the probe is adjusted parallel to the central axis OP of the tube, and the distance from the OP-segment is translated, which is called the eccentricity X (determined by the incident angle of the acoustic wave), so that the sound wave is inclined to the surface of the tube. After being refracted, it is transmitted inside the pipe material and is guaranteed to reach the inner wall of the pipe.
② Deflection method: the axis of the probe coincides with the central axis OP of the tube, and the pivot point on the probe is deflected by a certain angle, so that the sound wave is inclined to the surface of the pipe, and is refracted and transmitted to the inside of the pipe material.
(1) Detection method. Ultrasonic inspection of thin wall tubing is mainly carried out by automatic detection. The forms are:
① The probe is fixed, and the steel pipe is spirally advanced by the mechanical transmission device, so that the probe moves relative to the axis of the pipe. A single-wafer water immersion line focusing probe and a single-channel A-type pulse reflection ultrasonic flaw detector are usually used to detect the longitudinal (distribution along the axis of the tube) defects in the inner and outer walls of the tube.
② The pipe is rotated by the mechanical transmission equipment. The probe is driven by the drive trolley to move at a uniform speed along the axis of the pipe. The probes, instruments and detection defects used are the same as ①.
③ While the probe is rotating, the pipe is fed straight by the mechanical transmission equipment. Generally, multiple probes with different functions and different forms are used. The multi-channel ultrasonic flaw detector is used to simultaneously detect the longitudinal, lateral and layer defects of the inner and outer walls of the pipe. At the same time, the wall thickness of the tube is measured and the ellipticity is checked.
The detection method has a high degree of automation, and can simultaneously detect multi-directional defects, and can be combined with a micro-processor or an automatic multi-recorder for automatic print recording, quality sorting and the like.
(2) Detection frequency. Due to the thin wall thickness of the tube and the small size for effective pairing. The defects are detected and generally use a frequency of 5 MHz or higher.
(3) Acoustic coupling.
Regardless of the detection method used, water-treated water is used as a coupling agent in the ultrasonic testing of small-diameter thin-walled tubes. The basic requirement is to ensure that the water is sufficiently wetted on the surface of the steel pipe without generating blisters and reducing the corrosion of water on the steel pipe material.
(4) Acoustic wave incident angle adjustment.
① Horizontal offset method: the axis of the probe is adjusted parallel to the central axis OP of the tube, and the distance from the OP-segment is translated, which is called the eccentricity X (determined by the incident angle of the acoustic wave), so that the sound wave is inclined to the surface of the tube. After being refracted, it is transmitted inside the pipe material and is guaranteed to reach the inner wall of the pipe.
② Deflection method: the axis of the probe coincides with the central axis OP of the tube, and the pivot point on the probe is deflected by a certain angle, so that the sound wave is inclined to the surface of the pipe, and is refracted and transmitted to the inside of the pipe material.
Tensile strength and yield strength
Tensile strength and yield strength are two important mechanical properties of metal materials. These two indices are closely related to the fatigue-resistant manufacturing and the service life of components.
Tensile strength is an index of mechanical properties of a metal material obtained by a uniaxial tensile test. Tensile strength represents the ability of a metal material to resist deformation and damage under external forces. Tensile strength = breaking load / initial cross-sectional area of the specimen.
When the metal has obvious plastic deformation, the cross-sectional area used in the calculation should be the true cross-sectional area measured after the break, and the obtained tensile strength is called the true tensile strength.
This tensile strength index is an index against the maximum deformation ability. In other words, when the deformation reaches this level, the material is broken, and under the condition of uniaxial stretching, no larger deformation can be found. It is a limit and is specific. The tensile sample can withstand the limits of the applied load and is therefore called Ultimate Tensile Strength.
Yield strength is also one of the important mechanical properties of metal materials. The yield strength represents the resistance of the metal material to the initial plastic deformation, and its English expression is Yield strength. In fact, this is not completely accurate, because some metal materials have obvious yield points on the tensile curve, while other metal materials have no obvious yield point, especially for some materials with uneven microstructure. Therefore, it is necessary to artificially define the corresponding yield resistance strength when the plastic deformation is to a certain extent. In fact, before the artificially defined plastic deformation value, the slip of the internal driving force of the metal has started, so it cannot accurately reflect the plastic deformation. Start.
There is also a parameter about yield strength and tensile strength, this parameter is the yield ratio! The yield ratio is the ratio of yield strength to tensile strength. The range is between 0 and 1. The yield ratio is one of the indicators for measuring the brittleness of steel. The greater the yield ratio, the smaller the difference between the yield strength and the tensile strength of the steel, the worse the plasticity of the steel and the greater the brittleness!
The destruction of the material begins with the yield point. The lower the yield ratio, the longer the material will break from the beginning to the fracture, and the higher the yield ratio, the shorter the time from the onset of the material to the fracture. The energy is converted into heat energy between the yield point and the break point.
Simply saying that the yield strength is high or the tensile strength is high, then the material is necessarily better or safer. Only steels with high yield strength and low yield ratio are safer.
Tensile strength is an index of mechanical properties of a metal material obtained by a uniaxial tensile test. Tensile strength represents the ability of a metal material to resist deformation and damage under external forces. Tensile strength = breaking load / initial cross-sectional area of the specimen.
When the metal has obvious plastic deformation, the cross-sectional area used in the calculation should be the true cross-sectional area measured after the break, and the obtained tensile strength is called the true tensile strength.
This tensile strength index is an index against the maximum deformation ability. In other words, when the deformation reaches this level, the material is broken, and under the condition of uniaxial stretching, no larger deformation can be found. It is a limit and is specific. The tensile sample can withstand the limits of the applied load and is therefore called Ultimate Tensile Strength.
Yield strength is also one of the important mechanical properties of metal materials. The yield strength represents the resistance of the metal material to the initial plastic deformation, and its English expression is Yield strength. In fact, this is not completely accurate, because some metal materials have obvious yield points on the tensile curve, while other metal materials have no obvious yield point, especially for some materials with uneven microstructure. Therefore, it is necessary to artificially define the corresponding yield resistance strength when the plastic deformation is to a certain extent. In fact, before the artificially defined plastic deformation value, the slip of the internal driving force of the metal has started, so it cannot accurately reflect the plastic deformation. Start.
There is also a parameter about yield strength and tensile strength, this parameter is the yield ratio! The yield ratio is the ratio of yield strength to tensile strength. The range is between 0 and 1. The yield ratio is one of the indicators for measuring the brittleness of steel. The greater the yield ratio, the smaller the difference between the yield strength and the tensile strength of the steel, the worse the plasticity of the steel and the greater the brittleness!
The destruction of the material begins with the yield point. The lower the yield ratio, the longer the material will break from the beginning to the fracture, and the higher the yield ratio, the shorter the time from the onset of the material to the fracture. The energy is converted into heat energy between the yield point and the break point.
Simply saying that the yield strength is high or the tensile strength is high, then the material is necessarily better or safer. Only steels with high yield strength and low yield ratio are safer.
High strength low alloy steel
High-strength low-alloy (HSLA) steels, or microalloyed steels, are designed to provide better mechanical properties and/or greater resistance to atmospheric corrosion than conventional carbon steels in the normal sense because they are designed to meet specific mechanical properties rather than a chemical composition.
The HSLA steels have low carbon contents (0.05-0.25% C) in order to produce adequate formability and weldability, and they have manganese contents up to 2.0%. Small quantities of chromium, nickel, molybdenum, copper, nitrogen, vanadium, niobium, titanium and zirconium are used in various combinations.
HSLA Classification:
Weathering steels, designated to exhibit superior atmospheric corrosion resistance.
Control-rolled steels, hot rolled according to a predetermined rolling schedule, designed to develop a highly deformed austenite structure that will transform to a very fine equiaxed ferrite structure on cooling.
Pearlite-reduced steels, strengthened by very fine-grain ferrite and precipitation hardening but with low carbon content and therefore little or no pearlite in the microstructure.
Microalloyed steels, with very small additions of such elements as niobium, vanadium, and/or titanium for refinement of grain size and/or precipitation hardening.
Acicular ferrite steel, very low carbon steels with sufficient hardenability to transform on cooling to a very fine high-strength acicular ferrite structure rather than the usual polygonal ferrite structure.
Dual-phase steels, processed to a micro-structure of ferrite containing small uniformly distributed regions of high-carbon martensite, resulting in a product with low yield strength and a high rate of work hardening, thus providing a high-strength steel of superior formability.
The various types of HSLA steels may also have small additions of calcium, rare earth elements, or zirconium for sulfide inclusion shape control.
The HSLA steels have low carbon contents (0.05-0.25% C) in order to produce adequate formability and weldability, and they have manganese contents up to 2.0%. Small quantities of chromium, nickel, molybdenum, copper, nitrogen, vanadium, niobium, titanium and zirconium are used in various combinations.
HSLA Classification:
Weathering steels, designated to exhibit superior atmospheric corrosion resistance.
Control-rolled steels, hot rolled according to a predetermined rolling schedule, designed to develop a highly deformed austenite structure that will transform to a very fine equiaxed ferrite structure on cooling.
Pearlite-reduced steels, strengthened by very fine-grain ferrite and precipitation hardening but with low carbon content and therefore little or no pearlite in the microstructure.
Microalloyed steels, with very small additions of such elements as niobium, vanadium, and/or titanium for refinement of grain size and/or precipitation hardening.
Acicular ferrite steel, very low carbon steels with sufficient hardenability to transform on cooling to a very fine high-strength acicular ferrite structure rather than the usual polygonal ferrite structure.
Dual-phase steels, processed to a micro-structure of ferrite containing small uniformly distributed regions of high-carbon martensite, resulting in a product with low yield strength and a high rate of work hardening, thus providing a high-strength steel of superior formability.
The various types of HSLA steels may also have small additions of calcium, rare earth elements, or zirconium for sulfide inclusion shape control.
Specification and requirements for marking of seamless steel tubes
In the relevant regulations, there are a series of regulations and requirements for seamless steel pipe marking. The specific requirements for the logo are as follows:
1. The seamless steel pipe manufacturer's logo should be eye-catching, firm, clear, standardized, and not easy to fade.
2. The mark shall include at least the following contents: the name and trademark of the seamless steel pipe manufacturer, the product standard number, the grade of the steel pipe, the product specification and the traceability identification number or telephone number. For precision seamless steel tubes, you can increase the main performance indicators and dimensional precision levels.
Seamless steel pipe marking
3. The standard can be printed, stamped, scrolled, printed, pasted imprint or hang tags, tag and other methods, the supplier can hang one or more signs method.
4. Steel pipes with an outer diameter of not less than 36 mm shall be started at a distance of not less than 200 mm from the end of the seamless steel pipe, and each of the marking methods shall be carried out.
5. For low-pressure fluid seamless steel pipe and thin-walled seamless steel pipe, seamless steel pipe and other general-purpose seamless steel pipe, cross-section seamless steel pipe, complex cross-section seamless steel pipe can not be every mark.
6. Pipe joints of seamless steel pipes for petroleum, gas, 3PE anticorrosion, etc., shall have the grade mark of seamless steel pipe.
7. In the case of a container package, a bracket welding package or a thin-walled seamless steel pipe set. A label or tag should be attached to the seamless steel pipe on the outer layer of the container, bracket, and thin-walled seamless steel pipe.
http://www.xysteelpipe.com/info/Specification-and-requirements-for-marking-of-seamless-steel-tubes-1556-1.htm
1. The seamless steel pipe manufacturer's logo should be eye-catching, firm, clear, standardized, and not easy to fade.
2. The mark shall include at least the following contents: the name and trademark of the seamless steel pipe manufacturer, the product standard number, the grade of the steel pipe, the product specification and the traceability identification number or telephone number. For precision seamless steel tubes, you can increase the main performance indicators and dimensional precision levels.
Seamless steel pipe marking
3. The standard can be printed, stamped, scrolled, printed, pasted imprint or hang tags, tag and other methods, the supplier can hang one or more signs method.
4. Steel pipes with an outer diameter of not less than 36 mm shall be started at a distance of not less than 200 mm from the end of the seamless steel pipe, and each of the marking methods shall be carried out.
5. For low-pressure fluid seamless steel pipe and thin-walled seamless steel pipe, seamless steel pipe and other general-purpose seamless steel pipe, cross-section seamless steel pipe, complex cross-section seamless steel pipe can not be every mark.
6. Pipe joints of seamless steel pipes for petroleum, gas, 3PE anticorrosion, etc., shall have the grade mark of seamless steel pipe.
7. In the case of a container package, a bracket welding package or a thin-walled seamless steel pipe set. A label or tag should be attached to the seamless steel pipe on the outer layer of the container, bracket, and thin-walled seamless steel pipe.
http://www.xysteelpipe.com/info/Specification-and-requirements-for-marking-of-seamless-steel-tubes-1556-1.htm
2019年11月7日星期四
Resistance welding tube process principle
The electric resistance welded pipe (ERW steel pipe) is a method in which a weld is combined and pressure is applied through an electrode, and the electric current is welded by the electric resistance generated by the contact surface of the joint and the adjacent region. When high-frequency currents pass through metal conductors, two strange effects occur: skin effect and proximity effect, high-frequency welding is to use these two effects to weld the steel pipe, these two effects are the basis for achieving high-frequency welding of metal. High-frequency welding uses the skin effect to concentrate the energy of the high-frequency current on the surface of the workpiece; the proximity effect is used to control the position and range of the high-frequency current flow path. The speed of the current is very fast, it can heat, melt and join the adjacent steel plate edges in a short time.
Geometric seamlessness is to remove the internal and external burrs of the ERW steel pipe. Due to the continuous improvement and improvement of the structure and cutter of the inner burr removal system, the removal of the inner burr of the large and medium diameter steel pipe has been well treated. The inner burr can be controlled at about -0.2mm to about 0.5mm.
Physical seamlessness means that there is a difference between the metallographic structure inside the weld and the base metal, which leads to a decrease in the mechanical properties of the weld zone, and measures need to be taken to make it uniform and uniform.
http://www.xysteelpipe.com/info/Resistance-welding-tube-process-principle-1544-1.htm
Geometric seamlessness is to remove the internal and external burrs of the ERW steel pipe. Due to the continuous improvement and improvement of the structure and cutter of the inner burr removal system, the removal of the inner burr of the large and medium diameter steel pipe has been well treated. The inner burr can be controlled at about -0.2mm to about 0.5mm.
Physical seamlessness means that there is a difference between the metallographic structure inside the weld and the base metal, which leads to a decrease in the mechanical properties of the weld zone, and measures need to be taken to make it uniform and uniform.
http://www.xysteelpipe.com/info/Resistance-welding-tube-process-principle-1544-1.htm
The importance of seamless steel tubes in the industrial sector
Seamless steel pipe is a special pipe material, including a wide range of applications. The most common materials are carbon steel and stainless steel. The specifications of replacement products are relatively easy. At present, many seamless steel pipe production , still use the small batch production method, this manufacturing method should be said to be the most common one, the mechanized production mode, to some extent, improve the production efficiency of seamless steel pipe, using the operation mode of the entire production line operation, greatly increase production.
The heating furnace used in the production of seamless steel tubes is a ring-shaped heating furnace. In addition to this type of heating furnace, there are other types of heating furnaces. Depending on the production of seamless steel tubes, there are also differences in specific heating methods.
After the heat treatment is completed, further processing, including straightening, finishing and inspection, is required to ensure that the quality of the seamless steel pipe is maintained at the highest level when it is on the scene, so the inspection steps are essential.
At the same time, the demand for various accessory materials is also increasing, especially for the demand for various pipe materials. Judging from the current market environment, various types of pipe materials are widely used, different types of pipes, and different fields of application. Among them, the most worth mentioning is the seamless steel pipe, which has a very significant advantage. Therefore, the scale of production will continue to expand.
When it comes to quality, the production process and inspection level of seamless steel tubes are also constantly improving. With the introduction of new technologies, both in terms of production efficiency and product quality, there are significant improvements and developments. The development is also a testimony to the success of the industrial sector. Especially in the fields of construction, machinery manufacturing, etc., the role played by seamless steel pipes is also not to be underestimated. In addition, in the field of pipeline transportation, seamless steel pipes also have significant advantages, which can greatly improve transportation safety.
The seamless steel pipe needs to be inspected for its mechanical properties before leaving the factory, especially the tensile strength, yield point, elongation after break and hardness index of the seamless steel pipe, so as to ensure that the seamless steel pipe can be Quality is guaranteed. According to the differences in specific fields of use, there are certain differences in the production process of seamless steel tubes. The more common ones are alloy structure and carbon structure. In the field of pipeline transportation, the utilization rate of seamless steel pipes is very high, because compared with other types of transportation methods, pipeline transportation is not only safe, but also relatively low in cost, so the demand for seamless steel pipe production will be relatively large.
The manufacturer also supplies some seamless steel pipes with special use, such as seamless steel tubes for boilers, seamless steel tubes for geological use, etc. This professionally produced pipe material can be of higher value in the industrial manufacturing field. Depending on the material, the price difference between seamless steel pipes is also great.
http://www.xysteelpipe.com/info/The-importance-of-seamless-steel-tubes-in-the-industrial-sector-1543-1.htm
The heating furnace used in the production of seamless steel tubes is a ring-shaped heating furnace. In addition to this type of heating furnace, there are other types of heating furnaces. Depending on the production of seamless steel tubes, there are also differences in specific heating methods.
After the heat treatment is completed, further processing, including straightening, finishing and inspection, is required to ensure that the quality of the seamless steel pipe is maintained at the highest level when it is on the scene, so the inspection steps are essential.
At the same time, the demand for various accessory materials is also increasing, especially for the demand for various pipe materials. Judging from the current market environment, various types of pipe materials are widely used, different types of pipes, and different fields of application. Among them, the most worth mentioning is the seamless steel pipe, which has a very significant advantage. Therefore, the scale of production will continue to expand.
When it comes to quality, the production process and inspection level of seamless steel tubes are also constantly improving. With the introduction of new technologies, both in terms of production efficiency and product quality, there are significant improvements and developments. The development is also a testimony to the success of the industrial sector. Especially in the fields of construction, machinery manufacturing, etc., the role played by seamless steel pipes is also not to be underestimated. In addition, in the field of pipeline transportation, seamless steel pipes also have significant advantages, which can greatly improve transportation safety.
The seamless steel pipe needs to be inspected for its mechanical properties before leaving the factory, especially the tensile strength, yield point, elongation after break and hardness index of the seamless steel pipe, so as to ensure that the seamless steel pipe can be Quality is guaranteed. According to the differences in specific fields of use, there are certain differences in the production process of seamless steel tubes. The more common ones are alloy structure and carbon structure. In the field of pipeline transportation, the utilization rate of seamless steel pipes is very high, because compared with other types of transportation methods, pipeline transportation is not only safe, but also relatively low in cost, so the demand for seamless steel pipe production will be relatively large.
The manufacturer also supplies some seamless steel pipes with special use, such as seamless steel tubes for boilers, seamless steel tubes for geological use, etc. This professionally produced pipe material can be of higher value in the industrial manufacturing field. Depending on the material, the price difference between seamless steel pipes is also great.
http://www.xysteelpipe.com/info/The-importance-of-seamless-steel-tubes-in-the-industrial-sector-1543-1.htm
2019年10月28日星期一
In which case, the steel pipe needs anti-corrosion treatment
There are three cases of steel pipe anti-corrosion treatment:
1) If it is used in a general warehouse or canopy or workshop, it is not required to be treated with antiseptic treatment;
2) If used in chemical workshops or in workshops or other structures with corrosive contact, anti-corrosion treatment is required;
3) There are special requirements for steel pipes;
The steel pipe anti-corrosion quota can be installed as follows
1, Enhance the adhesion of the topcoat to the substrate to prevent the coating from penetrating too much into the substrate.
2, anti-alkali. The enclosed base alkali penetrates into the coating to reduce erosion of the topcoat.
3, Anti-rust, to prevent the corrosion of the top paint after the iron products in the base layer are rusted. In addition, the use of a primer can also enhance the texture of the system, save the amount of topcoat and shorten the construction time. Direct construction without primer will affect the appearance and texture of the paint film, and may also cause problems such as chalking. Metal coating without primer can not achieve effective rust prevention.
1) If it is used in a general warehouse or canopy or workshop, it is not required to be treated with antiseptic treatment;
2) If used in chemical workshops or in workshops or other structures with corrosive contact, anti-corrosion treatment is required;
3) There are special requirements for steel pipes;
The steel pipe anti-corrosion quota can be installed as follows
1, Enhance the adhesion of the topcoat to the substrate to prevent the coating from penetrating too much into the substrate.
2, anti-alkali. The enclosed base alkali penetrates into the coating to reduce erosion of the topcoat.
3, Anti-rust, to prevent the corrosion of the top paint after the iron products in the base layer are rusted. In addition, the use of a primer can also enhance the texture of the system, save the amount of topcoat and shorten the construction time. Direct construction without primer will affect the appearance and texture of the paint film, and may also cause problems such as chalking. Metal coating without primer can not achieve effective rust prevention.
2019年10月27日星期日
Introduction of alloy steel tube
The alloy steel tube is mainly used for the heating surface tube of low and medium pressure boilers (the working pressure is generally not more than 5.88Mpa and the working temperature is below 450°C); it is used for high pressure boilers (the working pressure is generally above 9.8Mpa, and the working temperature is 450°C～650 °C), heating surface pipe, economizer, superheater, reheater, petrochemical industrial pipe, etc.
High-pressure alloy pipe grade: 15CrMoG, 12Cr2MoG, 12Cr1MoVG, 12Cr2MoWVTiB, 10Cr9Mo1VNb, SA210A1, SA210C, SA213 T11, SA213 T12, SA213 T22, SA213 T23, SA213 T91, SA213 T92, ST45.8/III, 15Mo3, 13CrMo44, 10CrMo910, etc.
1, Application
The main purpose of alloy steel pipe is used in high-pressure high-temperature pipelines and equipment such as power plants, nuclear power, high-pressure boilers, high-temperature superheaters and reheaters. It is made of high-quality carbon steel, alloy structural steel and stainless steel. It is formed by hot rolling (extrusion, expansion) or cold rolling (drawing).
2, Advantages
It can be 100% recycled, in line with the national strategy of environmental protection, energy saving and resource conservation. The national policy encourages the expansion of the application field of high-pressure alloy tubes. At present, China's alloy tube consumption accounts for half of the total amount of steel in developed countries, and the expansion of alloy tube use provides a broader space for industry development. According to the research of the expert group of the alloy pipe branch of China Special Steel Association, the demand for long-term high-pressure alloy pipe in China will increase by 10-12% annually.
3, Contact and difference with seamless pipes
The alloy pipe is defined by the production material (that is, the material). As the name suggests, it is the pipe made of alloy; and the seamless pipe is defined by the production process (seam seamless), which is different from the seamless pipe. There are seam pipes, including straight seam welded pipes and spiral welded pipes.
4, Standard
The alloy tube has a hollow section and is used as a conduit for transporting fluids, such as pipes for transporting petroleum, natural gas, gas, water, and certain solid materials. Compared with solid steel such as round steel, alloy steel pipe has light weight when the bending and torsional strength are the same. Alloy steel pipe is an economical section steel, which is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipe and automobile transmission. Shafts, bicycle frames, and steel scaffolding used in construction. The use of alloy steel pipe to manufacture ring parts can improve the material utilization rate, simplify the manufacturing process, save materials and processing man-hours, such as rolling bearing rings, jack sleeves, etc., and have been widely used in steel pipes. Alloy steel pipes are also indispensable materials for various conventional weapons, and barrels, barrels, etc. are all made of steel pipes. Alloy steel pipes can be divided into round pipes and shaped pipes according to the shape of the cross-sectional area. Since the area of the circle is the largest under the condition of equal circumference, more fluid can be transported by the circular tube. In addition, the circular section is subjected to a relatively uniform force when subjected to internal or external radial pressure, and therefore, most of the steel pipes are round pipes.
High-pressure alloy pipe grade: 15CrMoG, 12Cr2MoG, 12Cr1MoVG, 12Cr2MoWVTiB, 10Cr9Mo1VNb, SA210A1, SA210C, SA213 T11, SA213 T12, SA213 T22, SA213 T23, SA213 T91, SA213 T92, ST45.8/III, 15Mo3, 13CrMo44, 10CrMo910, etc.
1, Application
The main purpose of alloy steel pipe is used in high-pressure high-temperature pipelines and equipment such as power plants, nuclear power, high-pressure boilers, high-temperature superheaters and reheaters. It is made of high-quality carbon steel, alloy structural steel and stainless steel. It is formed by hot rolling (extrusion, expansion) or cold rolling (drawing).
2, Advantages
It can be 100% recycled, in line with the national strategy of environmental protection, energy saving and resource conservation. The national policy encourages the expansion of the application field of high-pressure alloy tubes. At present, China's alloy tube consumption accounts for half of the total amount of steel in developed countries, and the expansion of alloy tube use provides a broader space for industry development. According to the research of the expert group of the alloy pipe branch of China Special Steel Association, the demand for long-term high-pressure alloy pipe in China will increase by 10-12% annually.
3, Contact and difference with seamless pipes
The alloy pipe is defined by the production material (that is, the material). As the name suggests, it is the pipe made of alloy; and the seamless pipe is defined by the production process (seam seamless), which is different from the seamless pipe. There are seam pipes, including straight seam welded pipes and spiral welded pipes.
4, Standard
The alloy tube has a hollow section and is used as a conduit for transporting fluids, such as pipes for transporting petroleum, natural gas, gas, water, and certain solid materials. Compared with solid steel such as round steel, alloy steel pipe has light weight when the bending and torsional strength are the same. Alloy steel pipe is an economical section steel, which is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipe and automobile transmission. Shafts, bicycle frames, and steel scaffolding used in construction. The use of alloy steel pipe to manufacture ring parts can improve the material utilization rate, simplify the manufacturing process, save materials and processing man-hours, such as rolling bearing rings, jack sleeves, etc., and have been widely used in steel pipes. Alloy steel pipes are also indispensable materials for various conventional weapons, and barrels, barrels, etc. are all made of steel pipes. Alloy steel pipes can be divided into round pipes and shaped pipes according to the shape of the cross-sectional area. Since the area of the circle is the largest under the condition of equal circumference, more fluid can be transported by the circular tube. In addition, the circular section is subjected to a relatively uniform force when subjected to internal or external radial pressure, and therefore, most of the steel pipes are round pipes.
What is a neck flange?Where is it used?
The neck flange, also known as the WN flange, has the primary function of joining two components into a given pipe system. Mounted in pairs, the contact between the two parts is guaranteed by the compression performed.
The neck flange was developed with the mission of transferring tension to the pipe. This transfer is intended to reduce the pressure at the base of the flange.
It can be used for any combination of pressure and temperature and furthermore, the neck flange attached to the pipe by a single butt weld gives lower residual stresses than the overlap type, for example. Assembly requires that the pipe be cut to the exact size and bevelled for the butt weld.
Other features of neck flange:
Tapered neck, above average strength, which prevents part deformation, beveled end, structure designed to withstand varying and high pressure and temperature, and weldability to the top of the flange.
And Prime Steel Pipe has the mission to offer the highest quality products at a fair price, able to meet the needs of its customers, achieving consistently better results, as its competence and talent are added to the technical capacity, experience and knowledge of the company. company to form a set of values that position it as a market leader.
The neck flange was developed with the mission of transferring tension to the pipe. This transfer is intended to reduce the pressure at the base of the flange.
It can be used for any combination of pressure and temperature and furthermore, the neck flange attached to the pipe by a single butt weld gives lower residual stresses than the overlap type, for example. Assembly requires that the pipe be cut to the exact size and bevelled for the butt weld.
Other features of neck flange:
Tapered neck, above average strength, which prevents part deformation, beveled end, structure designed to withstand varying and high pressure and temperature, and weldability to the top of the flange.
And Prime Steel Pipe has the mission to offer the highest quality products at a fair price, able to meet the needs of its customers, achieving consistently better results, as its competence and talent are added to the technical capacity, experience and knowledge of the company. company to form a set of values that position it as a market leader.
2019年10月15日星期二
Analysis of cracking reason on steel tube surface
Surface microcracks of lsaw steel pipe impact on product quality greatly, ranging from commuted, while in retirement, especially niobium, vanadium, titanium Longitudinal most prominent, has seriously affected the improvement of product quality and finished product rate. This not only gives the enterprise has brought huge economic losses, but also restricts the development of varieties of plate production line. Longitudinal surface microcracks mainly has edge crack, longitudinal, star cracks, its causes both improper rolling process parameter control, there are abnormal production of continuous casting process, the slab cracks genetic, residual element enrichment.
Longitudinal surface microcracks severely affect product quality. Longitudinal surface micro cracks main reason is the continuous casting mold copper coating off. This aspect will lead to copper penetration into the solidified shell austenite grain boundaries, grain boundary cracks; on the other hand will be uneven due to thermal stress cracks and crack sensitivity containing titanium steel strong performance is particularly evident . Control measures: To improve the quality of mold copper, copper to prevent dew; strengthen inspection before production of slab quality and production after Longitudinal; Longitudinal protection through good casting and other measures to improve Longitudinal steel cleanliness.
Longitudinal surface microcracks severely affect product quality. Longitudinal surface micro cracks main reason is the continuous casting mold copper coating off. This aspect will lead to copper penetration into the solidified shell austenite grain boundaries, grain boundary cracks; on the other hand will be uneven due to thermal stress cracks and crack sensitivity containing titanium steel strong performance is particularly evident . Control measures: To improve the quality of mold copper, copper to prevent dew; strengthen inspection before production of slab quality and production after Longitudinal; Longitudinal protection through good casting and other measures to improve Longitudinal steel cleanliness.
Prewelding process of LSAW steel tube
LSAW steel pipes (UOE, JCOE) manufacturing processes, welding processes are set to continuous advance. Its role is to be finalized after the tube forming, shaping and positioning within the weld seam on the back cover, in order to ensure the pipe dimensions and is conducive to tube welded pipe to improve quality and production efficiency.
Pre-welding process
After forming the tube by the next roller conveyor transported to a pre-welder's torch, rising rotating roll, rotate to adjust an open position to weld at the top of both sides of the pressure on the pressure roller and the pressure roller so that the tube seam, drop gun and adjust the tracking of the weld seam, open the protective gas and cooling water, start welding, welding condition monitoring, welded to the tube end welding arc stops (automatic delay stop gas), lift the gun and the top pressure rollers, pipe welder pre sent , pipe ends and welding defects.
Pre-welding process characteristics
Pre-welding using Ar + CO2 mixed gas shielded arc welding, continuous welding seam on the back of the tube to move at a faster speed. Since the bevel angle, tube shape, the tube along the longitudinal direction of the opening and both sides of the plate edge distortion factors of inequality, forming the seam after seam quality is not stable, larger changes. Need to change the tube seam welding, the arc of a steady state, the weld position deviated from the case and other real-time tracking and adjusted accordingly. Thus presoldered have welding speed, impact seam quality factors, changes and adjustments randomness and other characteristics.
Pre-welding process
After forming the tube by the next roller conveyor transported to a pre-welder's torch, rising rotating roll, rotate to adjust an open position to weld at the top of both sides of the pressure on the pressure roller and the pressure roller so that the tube seam, drop gun and adjust the tracking of the weld seam, open the protective gas and cooling water, start welding, welding condition monitoring, welded to the tube end welding arc stops (automatic delay stop gas), lift the gun and the top pressure rollers, pipe welder pre sent , pipe ends and welding defects.
Pre-welding process characteristics
Pre-welding using Ar + CO2 mixed gas shielded arc welding, continuous welding seam on the back of the tube to move at a faster speed. Since the bevel angle, tube shape, the tube along the longitudinal direction of the opening and both sides of the plate edge distortion factors of inequality, forming the seam after seam quality is not stable, larger changes. Need to change the tube seam welding, the arc of a steady state, the weld position deviated from the case and other real-time tracking and adjusted accordingly. Thus presoldered have welding speed, impact seam quality factors, changes and adjustments randomness and other characteristics.
Application of High Pressure Boiler Tube In Life
The rapid development of the national economy has led to the improvement of people's living standards, which have contributed to the development of the power industry. The power industry is environmentally viable and in line with our sustainable development strategy. According to China's resources, China is still dominated by thermal power at this stage and for a long time to come.
It is said that the electric power industry should mention high-pressure boiler tubes. The boiler tubes are steels that are open at both ends and have a hollow section. The steel with a relatively large length and the surrounding area can be divided into seamless steel pipes and welded steel pipes according to the production method. Dimensions (such as outer diameter or side length) and wall thickness indicate a wide range of sizes, from small diameter capillaries to large diameter pipes up to several meters in diameter. Steel pipes can be used in pipelines, thermal equipment, machinery industry, petroleum geological exploration, containers, chemical industry and special applications. In general, the high-pressure boiler tube is also a kind of seamless steel pipe, and its production process is the same as that of the seamless steel pipe. However, high-pressure boiler tubes are important components of power station boilers, used to manufacture high-pressure and ultra-high-pressure power station boilers, and are used to build large-scale thermal power plants.
Therefore, high-pressure boiler tubes are often in a high-temperature, high-pressure environment, so the requirements for his raw material billets are required. It is very strict and requires high durability and high corrosion resistance, oxidation resistance, and good stability.This will require you to shop around when you choose a high-pressure boiler tube, compare the price, but also to compare the quality.
http://www.xysteelpipe.com/info/Application-of-High-Pressure-Boiler-Tube-In-Life-1528-1.htm
It is said that the electric power industry should mention high-pressure boiler tubes. The boiler tubes are steels that are open at both ends and have a hollow section. The steel with a relatively large length and the surrounding area can be divided into seamless steel pipes and welded steel pipes according to the production method. Dimensions (such as outer diameter or side length) and wall thickness indicate a wide range of sizes, from small diameter capillaries to large diameter pipes up to several meters in diameter. Steel pipes can be used in pipelines, thermal equipment, machinery industry, petroleum geological exploration, containers, chemical industry and special applications. In general, the high-pressure boiler tube is also a kind of seamless steel pipe, and its production process is the same as that of the seamless steel pipe. However, high-pressure boiler tubes are important components of power station boilers, used to manufacture high-pressure and ultra-high-pressure power station boilers, and are used to build large-scale thermal power plants.
Therefore, high-pressure boiler tubes are often in a high-temperature, high-pressure environment, so the requirements for his raw material billets are required. It is very strict and requires high durability and high corrosion resistance, oxidation resistance, and good stability.This will require you to shop around when you choose a high-pressure boiler tube, compare the price, but also to compare the quality.
http://www.xysteelpipe.com/info/Application-of-High-Pressure-Boiler-Tube-In-Life-1528-1.htm
2019年10月14日星期一
Various factors affecting the hardenability of steel
Due to the high hardenability and strengthening the role of alloying elements, some high strength martensitic stainless steel, high speed tool steel and high-strength alloy steel. Often in the quench (or tempering) after a high-temperature tempering, the steel carbide appropriate aggregation obtain coarse carbide particles tempered sorbite organization (with ball annealing similar organizations) Thus, this delivery steel state has good cutting performance cooling directly after delivery, known as hot rolling or forging state, after hot rolling or forging steel and not subject to special heat treatment. Hot rolling (forging) termination temperature is generally 800-900 ℃, after the general natural cooling in the air, and thus hot rolling (forging) state corresponds to normalizing. Unlike strict normalizing heating temperature control, the difference because of hot-rolled (forging) termination temperature high and low. Thus it is well done microstructure and properties of the steel shaken ratio.
1. That many steel companies controlled rolling, since the finishing temperature control is very strict and forced cooling after finish rolling to take measures so that grain refinement of steel, delivery of steel with high mechanical properties. Since the appearance of the skin is covered with a layer of iron oxide, which has a certain degree of corrosion resistance, as stringent storage requirements are not kept cold drawn (rolled) state delivery of steel, medium-sized steel, thick steel plate can be in the open air yard or through thatch cover and store the non-twist and controlled cooling hot rod location is the truth, hot-rolled (forging) state of delivery than ordinary steel hot rod performance.
2. Cold drawn (rolled) on steel hardenability without any heat treatment and direct delivery, the status of the cold drawing, cold-rolled steel cold forming. Called cold-drawn or cold-rolled condition. Cold-drawn steel dimensions (rolled) state of high accuracy, good surface quality, appearance roughness is low, and have high mechanical properties, compared with the hot rolling (forging) state. Since the cold drawn (rolled) state of delivery without scale steel outer cover, and there is a big stress, vulnerable to corrosion or rust, and thus cold drawn (rolled) state steel, packaging, storage and transportation are more stringent requirements, generally need to be in the custody of the Treasury, and the Treasury should pay attention to the temperature and humidity control the delivery state within the state, said normalizing. Since normalizing heating temperature (hypoeutectoid steel as Ac3 + 3050 ° C eutectoid steel as Accm + 3050 ° C than hot-end temperature control strict.
3. Before normalizing the status of the steel factory and normalizing heat treatment. Thus the structure of the steel, a uniform performance. Since normalizing cooling faster, compared to steel annealed state. Pearlite structure of the steel increased number of pearlite lamellar and grain refinement of steel, and thus have higher mechanical properties, and help to improve the low carbon steel widmanstatten and eutectoid steel cementite net, for further heat treatment of the finished product do organizational readiness.
1. That many steel companies controlled rolling, since the finishing temperature control is very strict and forced cooling after finish rolling to take measures so that grain refinement of steel, delivery of steel with high mechanical properties. Since the appearance of the skin is covered with a layer of iron oxide, which has a certain degree of corrosion resistance, as stringent storage requirements are not kept cold drawn (rolled) state delivery of steel, medium-sized steel, thick steel plate can be in the open air yard or through thatch cover and store the non-twist and controlled cooling hot rod location is the truth, hot-rolled (forging) state of delivery than ordinary steel hot rod performance.
2. Cold drawn (rolled) on steel hardenability without any heat treatment and direct delivery, the status of the cold drawing, cold-rolled steel cold forming. Called cold-drawn or cold-rolled condition. Cold-drawn steel dimensions (rolled) state of high accuracy, good surface quality, appearance roughness is low, and have high mechanical properties, compared with the hot rolling (forging) state. Since the cold drawn (rolled) state of delivery without scale steel outer cover, and there is a big stress, vulnerable to corrosion or rust, and thus cold drawn (rolled) state steel, packaging, storage and transportation are more stringent requirements, generally need to be in the custody of the Treasury, and the Treasury should pay attention to the temperature and humidity control the delivery state within the state, said normalizing. Since normalizing heating temperature (hypoeutectoid steel as Ac3 + 3050 ° C eutectoid steel as Accm + 3050 ° C than hot-end temperature control strict.
3. Before normalizing the status of the steel factory and normalizing heat treatment. Thus the structure of the steel, a uniform performance. Since normalizing cooling faster, compared to steel annealed state. Pearlite structure of the steel increased number of pearlite lamellar and grain refinement of steel, and thus have higher mechanical properties, and help to improve the low carbon steel widmanstatten and eutectoid steel cementite net, for further heat treatment of the finished product do organizational readiness.
Low carbon steel welding process
Low carbon steel has a carbon content of ≤0.25%, and its plasticity is good. Generally, it has no tendency to harden, is not sensitive to the welding process, and has good weldability. When welding such steels, special process measures are not required, and heat treatment (except electroslag welding) is usually not required after welding.
For low-carbon steel structures with a thickness greater than 50 mm, high-current multi-layer welding is commonly used, and internal stress annealing is eliminated after welding. When the structure with high welding rigidity in a low temperature environment is large, the temperature difference between the parts of the weldment is large, and the deformation is limited. The welding process is prone to generate large internal stress, which may cause cracking of the structure. Therefore, preheating before welding should be performed.
Low carbon steel can be welded by various welding methods, and the most widely used are electrode arc welding, submerged arc welding, electroslag welding, gas shielded welding and electric resistance welding.
When welding structural steel by fusion welding, the selection of welding materials and processes should mainly ensure the strength of welded joints and workpiece materials. Welding rod arc welding is generally low carbon steel structure, E4313 (J421), E4303 (J422), E4320 (J424) welding rod can be selected. When welding dynamic load structures and complex structures, E4316 (J426), E4315 (J427) or E5015 (J507) electrodes should be used. For submerged arc welding, H08A or H08MnA welding wire with flux 431 is generally used for welding.
For low-carbon steel structures with a thickness greater than 50 mm, high-current multi-layer welding is commonly used, and internal stress annealing is eliminated after welding. When the structure with high welding rigidity in a low temperature environment is large, the temperature difference between the parts of the weldment is large, and the deformation is limited. The welding process is prone to generate large internal stress, which may cause cracking of the structure. Therefore, preheating before welding should be performed.
Low carbon steel can be welded by various welding methods, and the most widely used are electrode arc welding, submerged arc welding, electroslag welding, gas shielded welding and electric resistance welding.
When welding structural steel by fusion welding, the selection of welding materials and processes should mainly ensure the strength of welded joints and workpiece materials. Welding rod arc welding is generally low carbon steel structure, E4313 (J421), E4303 (J422), E4320 (J424) welding rod can be selected. When welding dynamic load structures and complex structures, E4316 (J426), E4315 (J427) or E5015 (J507) electrodes should be used. For submerged arc welding, H08A or H08MnA welding wire with flux 431 is generally used for welding.
2019年10月8日星期二
Anti-corrosion and heat preservation performance of spiral steel tube
Anti-corrosion insulation pipe with corrosion resistance of steel, and has good insulation properties, has been widely used and promoted in building construction, and constantly improve and spread. Corrosion pipe insulation having different processing types and methods, different processing method to determine the pipe have different properties and functions, and the use range also changes. As the name suggests, it is to increase the number of external spiral steel pipe corrosion insulation class protection, in order to achieve low temperature can be used. In general, the use of second degree pipe insulation inorganic zinc-rich paint, which temperature ≥400 ℃, belonging to corrosion coating, conduit port is used polyethylene film called 3-layer PE or using cold sealing tapes to achieve the previously installed to prevent moisture entering into the water or construction.
Spiral steel pipe insulation for high temperature, water and fuel pumps, chemical pump corrosive. Insulation pipeline centrifugal pump series products with low noise, performance, energy efficient and reliable. The insulation material used is a multi-layer bandaging wrong seam, so it is effective to reduce the heat loss, but also able to control the jacket surface measures to prevent the generation of cold bridges, so that the outer coating of temperature control is guaranteed. Spiral steel pipe wrapped with insulation material multilayer reflective layer of aluminum foil, which can effectively reduce the loss of heat, and can make the steam pipe can be more economical and reasonable. Anti-corrosion steel pipe insulation is a good corrosion resistance, along with good insulation properties, has been widely used and promoted in the design and construction, the current and constantly perfected and popularized. Spiral steel also have different types and methods of processing, while the different processing method to determine the pipe have different properties and functions, and range will change!
Spiral steel pipe insulation for high temperature, water and fuel pumps, chemical pump corrosive. Insulation pipeline centrifugal pump series products with low noise, performance, energy efficient and reliable. The insulation material used is a multi-layer bandaging wrong seam, so it is effective to reduce the heat loss, but also able to control the jacket surface measures to prevent the generation of cold bridges, so that the outer coating of temperature control is guaranteed. Spiral steel pipe wrapped with insulation material multilayer reflective layer of aluminum foil, which can effectively reduce the loss of heat, and can make the steam pipe can be more economical and reasonable. Anti-corrosion steel pipe insulation is a good corrosion resistance, along with good insulation properties, has been widely used and promoted in the design and construction, the current and constantly perfected and popularized. Spiral steel also have different types and methods of processing, while the different processing method to determine the pipe have different properties and functions, and range will change!
Method for Distinguishing the Quality of Seamless Steel Pipes
The use of seamless steel pipes is becoming wider and wider. When we choose seamless steel pipes, we must test the quality of seamless steel pipes. The following small series is detailed for everyone:
1. The fake and inferior seamless steel pipe is easy to be scratched, because the equipment of the fake and inferior seamless steel pipe manufacturers is simple, easy to produce burrs and scratch the surface of the steel. Deep scratches reduce the strength of the steel.
2. The counterfeit seamless steel pipe has no metallic luster and is light red or similar to pig iron.
3. The cross-fabricity of the counterfeit seamless steel pipe is thin and low, and the phenomenon of filling and dissatisfaction often occurs. The reason is that the manufacturer has to achieve a large negative tolerance, and the reduction of the first few passes of the finished product is too large, the iron type is small, and the hole type is not full.
4. The cross-section of the counterfeit semanufacturer has to reduce the amount of the two rolls in front of the finished roll in order to save material. The strength of this seamless steel pipe is greatly reduced, and it does not conform to the seamless steel pipe. The standard of the dimensions.
5. The composition of high-quality seamless steel pipe is uniform, the tonnage of the cold-shearing machine is high, the end face of the cutting head is smooth and tidy, and the surface of the inferior seamless steel pipe is often poor due to poor material, and the end face of the cutting head often has a phenomenon of falling meat, that is, unevenness, and no Metallic luster. And because the fake and inferior manufacturers have fewer heads, big ears will appear at the head and tail.
6. The fake and inferior seamless steel pipe material contains many impurities, the density of the steel is small, and the size is too bad, so in the absence of the vernier caliper, it can be weighed and checked. In general, the whole box weighing effect will be better, mainly considering the problem of cumulative error and probability theory.
http://www.xysteelpipe.com/info/Method-for-Distinguishing-the-Quality-of-Seamless-Steel-Pipes-1520-1.htm
1. The fake and inferior seamless steel pipe is easy to be scratched, because the equipment of the fake and inferior seamless steel pipe manufacturers is simple, easy to produce burrs and scratch the surface of the steel. Deep scratches reduce the strength of the steel.
2. The counterfeit seamless steel pipe has no metallic luster and is light red or similar to pig iron.
3. The cross-fabricity of the counterfeit seamless steel pipe is thin and low, and the phenomenon of filling and dissatisfaction often occurs. The reason is that the manufacturer has to achieve a large negative tolerance, and the reduction of the first few passes of the finished product is too large, the iron type is small, and the hole type is not full.
4. The cross-section of the counterfeit semanufacturer has to reduce the amount of the two rolls in front of the finished roll in order to save material. The strength of this seamless steel pipe is greatly reduced, and it does not conform to the seamless steel pipe. The standard of the dimensions.
5. The composition of high-quality seamless steel pipe is uniform, the tonnage of the cold-shearing machine is high, the end face of the cutting head is smooth and tidy, and the surface of the inferior seamless steel pipe is often poor due to poor material, and the end face of the cutting head often has a phenomenon of falling meat, that is, unevenness, and no Metallic luster. And because the fake and inferior manufacturers have fewer heads, big ears will appear at the head and tail.
6. The fake and inferior seamless steel pipe material contains many impurities, the density of the steel is small, and the size is too bad, so in the absence of the vernier caliper, it can be weighed and checked. In general, the whole box weighing effect will be better, mainly considering the problem of cumulative error and probability theory.
http://www.xysteelpipe.com/info/Method-for-Distinguishing-the-Quality-of-Seamless-Steel-Pipes-1520-1.htm
2019年9月29日星期日
LSAW steel tube vs SSAW steel tube
1. Submerged Arc Welding Process Difference.
Compared with spiral submerged arc welding process, longitudinal submerged arc welding process can inevitably have a lot of T-weld, so the existence of welding defects has great increased. The welding residual T-welds stress is large, and the weld metal are often in three-dimensional stress state which can increase the likelihood of cracks. Besides, according to the provisions of submerged arc welding process, each weld shall have the arc at the place and extinction. However, in each longitudinal submerged arc welding ring, it is unable to meet the conditions which causes more weld defects during longitudinal submerged arc welding process.
2. Production Range Difference
Under the same operating pressure to produce the same outside diameter longitudinal weld pipe and spiral weld pipe, spiral weld pipe can produce thinner wall thickness pipe than longitudinal weld pipe. Because when the pressure in the pipe to withstand, it typically produces two main stress on the pipe wall. These two main stress are radial stress and axial stress. On spiral weld pipe, these two main stress are divided by the helix angle of the weld, therefore synthetic spiral weld stresses are the main stress.
3. The Hydro Static Burst Strength
The yield stress and burst pressure on spiral weld pipe is lower than the longitudinal weld pipe, even though there are certain relevant comparison test has says the yield pressure and burst pressure measured and theoretical values are basic the same on spiral and longitudinal weld pipe. In the blasting test, it also proved that the hoop blasting mouth deformation rate for spiral weld pipe is significantly greater than the longitudinal weld pipe. It confirmed that spiral weld pipe has a greater plastic deformation than longitudinal weld pipe.
4. Toughness Difference
Compared with the same specification spiral weld pipe and longitudinal weld pipe, spiral weld pipe has a higher impact of toughness. With the increasing needs for large diameter pipe with high strength and with the development of new steel grades, It requires greater ductile fracture tip.
5. Fatigue Strength Difference
With the same test data in the same area, under the same pipe distribution and resistance, longitudinal submerged arc weld pipe has a higher level of fatigue strength. Because of the transfer pipeline output volume changes, in the actual operation, the pipe is subjected to random alternating loads of action. It is very significant to judge the life of pipeline by learning the cycle fatigue strength of steel.
Compared with spiral submerged arc welding process, longitudinal submerged arc welding process can inevitably have a lot of T-weld, so the existence of welding defects has great increased. The welding residual T-welds stress is large, and the weld metal are often in three-dimensional stress state which can increase the likelihood of cracks. Besides, according to the provisions of submerged arc welding process, each weld shall have the arc at the place and extinction. However, in each longitudinal submerged arc welding ring, it is unable to meet the conditions which causes more weld defects during longitudinal submerged arc welding process.
2. Production Range Difference
Under the same operating pressure to produce the same outside diameter longitudinal weld pipe and spiral weld pipe, spiral weld pipe can produce thinner wall thickness pipe than longitudinal weld pipe. Because when the pressure in the pipe to withstand, it typically produces two main stress on the pipe wall. These two main stress are radial stress and axial stress. On spiral weld pipe, these two main stress are divided by the helix angle of the weld, therefore synthetic spiral weld stresses are the main stress.
3. The Hydro Static Burst Strength
The yield stress and burst pressure on spiral weld pipe is lower than the longitudinal weld pipe, even though there are certain relevant comparison test has says the yield pressure and burst pressure measured and theoretical values are basic the same on spiral and longitudinal weld pipe. In the blasting test, it also proved that the hoop blasting mouth deformation rate for spiral weld pipe is significantly greater than the longitudinal weld pipe. It confirmed that spiral weld pipe has a greater plastic deformation than longitudinal weld pipe.
4. Toughness Difference
Compared with the same specification spiral weld pipe and longitudinal weld pipe, spiral weld pipe has a higher impact of toughness. With the increasing needs for large diameter pipe with high strength and with the development of new steel grades, It requires greater ductile fracture tip.
5. Fatigue Strength Difference
With the same test data in the same area, under the same pipe distribution and resistance, longitudinal submerged arc weld pipe has a higher level of fatigue strength. Because of the transfer pipeline output volume changes, in the actual operation, the pipe is subjected to random alternating loads of action. It is very significant to judge the life of pipeline by learning the cycle fatigue strength of steel.
ERW steel tube vs UOE steel tube
ERW Steel Pipe is different from UOE Steel Pipe, the difference are as follows:
1. The Raw Materials and Production Capacity Difference
The material for producing ERW Steel Pipe is hot-rolled coil or strips, while for producing UOE Steel Pipe we use hot-rolled steel. Therefore, ERW Steel Pipe can achieve a continuous pipeline operations, high production efficiency, low production costs. For UOE Steel Pipe, it can not achieve a continuous pipeline operations, low productivity, high production cost. The maximum thickness for ERW Steel Pipe can reach 25mm, and the maximum outside diameter for ERW Steel Pipe can achieve 660mm. However, the maximum wall thickness for UOE Steel Pipe is 40mm, and the maximum production outside diameter is limited by the width of the steel sheet, in current day, the maximum production outside diameter for UOE Steel Pipe is 1422mm.
2. Welding Difference
Compared with UOE Steel Pipe, one of the advantages of ERW Steel Pipe is that there is no need to have additional wire during the welding process.
3. Appearance Difference
During the production process, ERW Steel Pipe requires inside and outside welds remove, so it has a anti-corrosive advantages compared with UOE Steel Pipe.
4. Application Difference
ERW Steel Pipe is mainly applied in natural gas, refined oil, crude oil, pulp and other terrestrial long-distance pipelines. UOE steel pipes are mainly used in high-voltage submarine long-distance pipelines, alpine area, land two/three/four types of areas.
1. The Raw Materials and Production Capacity Difference
The material for producing ERW Steel Pipe is hot-rolled coil or strips, while for producing UOE Steel Pipe we use hot-rolled steel. Therefore, ERW Steel Pipe can achieve a continuous pipeline operations, high production efficiency, low production costs. For UOE Steel Pipe, it can not achieve a continuous pipeline operations, low productivity, high production cost. The maximum thickness for ERW Steel Pipe can reach 25mm, and the maximum outside diameter for ERW Steel Pipe can achieve 660mm. However, the maximum wall thickness for UOE Steel Pipe is 40mm, and the maximum production outside diameter is limited by the width of the steel sheet, in current day, the maximum production outside diameter for UOE Steel Pipe is 1422mm.
2. Welding Difference
Compared with UOE Steel Pipe, one of the advantages of ERW Steel Pipe is that there is no need to have additional wire during the welding process.
3. Appearance Difference
During the production process, ERW Steel Pipe requires inside and outside welds remove, so it has a anti-corrosive advantages compared with UOE Steel Pipe.
4. Application Difference
ERW Steel Pipe is mainly applied in natural gas, refined oil, crude oil, pulp and other terrestrial long-distance pipelines. UOE steel pipes are mainly used in high-voltage submarine long-distance pipelines, alpine area, land two/three/four types of areas.
Manufacturers and suppliers of welded steel tubes
Tianjin Xinyue Steel Group as a welded steel pipe supplier in China, offering the best price of cold drawn welded pipe is our competitive advantages. we can offer all kinds of cold drawn welded pipe in stock.
The cold drawn welded steel pipe term is often used to describe special products from a processing technology of welded steel pipe. Cold drawn welded pipe has accurate specification, good concentration, uniform wall thickness, diameter and mechanical properties, good degree of hardness, resistance to bending and tensile properties, high standard of surface polishing and ensure the integrity of the welding. This kind of steel pipe still need further fine processing before using. Cold drawn welded steel pipe need to plaquette, then Individuation to shaft for drawing again. We can produce a variety of specifications of the finished tube by this way and may use several kinds of metal stamping and shaft during period.
Cold drawn welded(DOM) technology is mainly used for mass production of the pipe of mechanical equipment (such as the hydraulic system) and solid core rod with the diameter close to the ideal inner diameter. If you need cold drawn welded steel pipe, you can contact us at any time, we will provide you the best price of cold drawn welded pipe.
The cold drawn welded steel pipe term is often used to describe special products from a processing technology of welded steel pipe. Cold drawn welded pipe has accurate specification, good concentration, uniform wall thickness, diameter and mechanical properties, good degree of hardness, resistance to bending and tensile properties, high standard of surface polishing and ensure the integrity of the welding. This kind of steel pipe still need further fine processing before using. Cold drawn welded steel pipe need to plaquette, then Individuation to shaft for drawing again. We can produce a variety of specifications of the finished tube by this way and may use several kinds of metal stamping and shaft during period.
Cold drawn welded(DOM) technology is mainly used for mass production of the pipe of mechanical equipment (such as the hydraulic system) and solid core rod with the diameter close to the ideal inner diameter. If you need cold drawn welded steel pipe, you can contact us at any time, we will provide you the best price of cold drawn welded pipe.
2019年9月18日星期三
Fire protection measures of seamless steel tube
Seamless steel pipes usually lose their load carrying capacity at temperatures of 450 to 650 ° C, causing large deformations, resulting in bending of steel columns and steel beams. As a result, they cannot be used due to excessive deformation.The unfired seamless steel pipe has a fire resistance limit of about 15 minutes. The length of this time is also related to the speed at which the component absorbs heat. The fire protection measures for several different seamless steel pipes are described below.
1. The outer layer. It is to add an outer layer on the surface of the seamless steel pipe, which can be cast in place or sprayed. The cast-in-place solid concrete cladding is usually reinforced with steel mesh or steel to limit shrinkage cracks and to ensure the strength of the casing.
2. Fill the water. Filling the hollow seamless steel pipe is the most effective protection against fire. This method enables the seamless steel pipe to maintain a lower temperature in the fire, and the water circulates in the seamless steel pipe to absorb the heat of the material itself. The heated water can be recirculated after cooling, or cold water can be introduced from the pipeline to replace the heated water.
3. Shielding. The seamless steel pipe is placed in a wall or ceiling made of refractory material, or the component is hidden in the space between the two walls, and the fireproofing purpose can be achieved by adding a little refractory material or increasing it. This is the most economical way to fire.
At present, high-rise seamless steel pipe construction is increasing, especially for some super high-rise buildings, which use a wider range of seamless steel pipe materials. In the event of a fire accident in a high-rise building, the fire will not be extinguished in a short period of time. This requires us to increase the fire protection of the building materials during the design of the building to enhance its fire resistance and to develop the necessary emergency within the building. Program to reduce casualties and property damage.
http://www.xysteelpipe.com/info/Fire-protection-measures-of-seamless-steel-tube-1510-1.htm
1. The outer layer. It is to add an outer layer on the surface of the seamless steel pipe, which can be cast in place or sprayed. The cast-in-place solid concrete cladding is usually reinforced with steel mesh or steel to limit shrinkage cracks and to ensure the strength of the casing.
2. Fill the water. Filling the hollow seamless steel pipe is the most effective protection against fire. This method enables the seamless steel pipe to maintain a lower temperature in the fire, and the water circulates in the seamless steel pipe to absorb the heat of the material itself. The heated water can be recirculated after cooling, or cold water can be introduced from the pipeline to replace the heated water.
3. Shielding. The seamless steel pipe is placed in a wall or ceiling made of refractory material, or the component is hidden in the space between the two walls, and the fireproofing purpose can be achieved by adding a little refractory material or increasing it. This is the most economical way to fire.
At present, high-rise seamless steel pipe construction is increasing, especially for some super high-rise buildings, which use a wider range of seamless steel pipe materials. In the event of a fire accident in a high-rise building, the fire will not be extinguished in a short period of time. This requires us to increase the fire protection of the building materials during the design of the building to enhance its fire resistance and to develop the necessary emergency within the building. Program to reduce casualties and property damage.
http://www.xysteelpipe.com/info/Fire-protection-measures-of-seamless-steel-tube-1510-1.htm
2019年9月17日星期二
Hot Rolled Tube Seamless Steel Tube
Hot rolled seamless steel tube: hot rolling is related to the cold drawn, hot rolling is performed above the recrystallization temperature of the rolling.
Hot-rolled seamless steel tube advantages:
Ingot casting can destroy tissue, grain refinement of steel and eliminate defects microstructure, so that the steel dense tissue mechanical properties are improved. This improvement is mainly reflected in the direction along the rolling direction to a certain extent, the steel is no longer isotropic; pouring formed bubbles, cracks and loose, can be welded at a high temperature and pressure.
Hot-rolled seamless stee tube disadvantages:
1. After hot rolling, the steel inside the non-metallic inclusions (mainly sulphide and oxide, and silicates) is pressed into the sheet, delamination (interlayer) phenomenon. Layered in the thickness direction of the steel tension performance deteriorated significantly, and there may be an interlayer tear weld shrinkage. Weld local strain-induced contraction of the yield point strain often reach several times larger than the load caused by the strain;
2. Residual stresses caused by uneven cooling. Residual stresses in the absence of external force from the internal equilibrium of stress, both hot-rolled steel section such various residual stress, the greater the cross-sectional size generally of steel, the residual stress is larger. Although the residual stress from equilibrium, but still has some influence on the performance of the steel members under loads. Terms such as deformation, stability, anti-fatigue effects may adversely.
3. Hot-rolled steel products, poor control of the thickness and width of the edge in this respect. We are familiar with thermal expansion and contraction, since the beginning of the hot rolling out even the length, thickness are standard, and finally cooled or there will be some negative difference, this negative difference edge width wider, thicker the more obvious manifestations. So for large steel for steel edge width, thickness, length, angle, and no law requires very precise edges.
Hot-rolled seamless steel tube process:
Round tube perforation → heating → three-roll rolling, rolling or extrusion → detached → sizing (or reducing) → cooling → straightening → hydrostatic test (or testing) → mark → storage
Hot-rolled seamless steel tube advantages:
Ingot casting can destroy tissue, grain refinement of steel and eliminate defects microstructure, so that the steel dense tissue mechanical properties are improved. This improvement is mainly reflected in the direction along the rolling direction to a certain extent, the steel is no longer isotropic; pouring formed bubbles, cracks and loose, can be welded at a high temperature and pressure.
Hot-rolled seamless stee tube disadvantages:
1. After hot rolling, the steel inside the non-metallic inclusions (mainly sulphide and oxide, and silicates) is pressed into the sheet, delamination (interlayer) phenomenon. Layered in the thickness direction of the steel tension performance deteriorated significantly, and there may be an interlayer tear weld shrinkage. Weld local strain-induced contraction of the yield point strain often reach several times larger than the load caused by the strain;
2. Residual stresses caused by uneven cooling. Residual stresses in the absence of external force from the internal equilibrium of stress, both hot-rolled steel section such various residual stress, the greater the cross-sectional size generally of steel, the residual stress is larger. Although the residual stress from equilibrium, but still has some influence on the performance of the steel members under loads. Terms such as deformation, stability, anti-fatigue effects may adversely.
3. Hot-rolled steel products, poor control of the thickness and width of the edge in this respect. We are familiar with thermal expansion and contraction, since the beginning of the hot rolling out even the length, thickness are standard, and finally cooled or there will be some negative difference, this negative difference edge width wider, thicker the more obvious manifestations. So for large steel for steel edge width, thickness, length, angle, and no law requires very precise edges.
Hot-rolled seamless steel tube process:
Round tube perforation → heating → three-roll rolling, rolling or extrusion → detached → sizing (or reducing) → cooling → straightening → hydrostatic test (or testing) → mark → storage
Limitations of SSAW steel tube
SSAW steel pipe also has its own shortcomings, spiral steel hollow section is used as a large number of pipeline fluids, such as transportation of oil, natural gas, gas, water and some solid materials, pipes and so on. Compared to other steel and solid steel bar, the same torsional strength in bending, lighter, is an economic cross-section steel, widely used in the manufacture of structural parts and mechanical parts, such as drill pipe, automotive drive shafts, bicycle rack and construction using steel scaffolding.
Steel pipe manufacturing annular parts, can improve material utilization, simplify the manufacturing process, saving material and machining time, such as bearing rings, jack sets, has been widely used to make steel. Steel or a variety of conventional weapons indispensable material, barrel, barrel would have to make steel. Pipe according to different cross-sectional shapes can be divided into tube and shaped tubes. Because in the perimeter of equal conditions, the largest area of a circle with a circular tube can carry more fluid. In addition, the circular cross section to withstand internal or external radial pressure, the force is uniform, so the vast majority of pipe is pipe.
However, the tube also has some limitations, such as under the conditions by plane bending, tube as good as square, rectangular tube large flexural strength, the skeleton of some farm machinery, steel and wood furniture on the popular square, rectangular tube. According to different uses should also have other special-shaped pipe cross-sectional shape.
Steel pipe manufacturing annular parts, can improve material utilization, simplify the manufacturing process, saving material and machining time, such as bearing rings, jack sets, has been widely used to make steel. Steel or a variety of conventional weapons indispensable material, barrel, barrel would have to make steel. Pipe according to different cross-sectional shapes can be divided into tube and shaped tubes. Because in the perimeter of equal conditions, the largest area of a circle with a circular tube can carry more fluid. In addition, the circular cross section to withstand internal or external radial pressure, the force is uniform, so the vast majority of pipe is pipe.
However, the tube also has some limitations, such as under the conditions by plane bending, tube as good as square, rectangular tube large flexural strength, the skeleton of some farm machinery, steel and wood furniture on the popular square, rectangular tube. According to different uses should also have other special-shaped pipe cross-sectional shape.
Quality problem of LSAW steel tube
In the LSAW steel pipe production process, because the primary process is in a hot state, so the heating operation is resolution product quality is very important process.
The heat with the furnace, according to their results, and reheating furnace is divided into two kinds; the former is used to billet heated from room temperature to the processing temperature; the latter is used in the process in the blank reheated to the required processing temperature.
Heating will be wrong in the outer surface of the tube surface may exhibit cracks, folds and migraine pain and other waste reason.
Furnace There are many ways, but the primary use is a ring furnace. This furnace has an annular hearth, it can slowly change the direction of the diameter of the blank along the bottom of the load from the entrance, a reversal can be used at the outlet of the heating and soaking temperature to the rule kind of stove. This operation is the key blank is heated uniformly heated to a temperature suitable for processing. Because a great impact on the quality of the perforation, that is, when the temperature of the process piercing is an important condition affecting the quality, it is generally the temperature of the billet piercing working is to manipulate.
The heat with the furnace, according to their results, and reheating furnace is divided into two kinds; the former is used to billet heated from room temperature to the processing temperature; the latter is used in the process in the blank reheated to the required processing temperature.
Heating will be wrong in the outer surface of the tube surface may exhibit cracks, folds and migraine pain and other waste reason.
Furnace There are many ways, but the primary use is a ring furnace. This furnace has an annular hearth, it can slowly change the direction of the diameter of the blank along the bottom of the load from the entrance, a reversal can be used at the outlet of the heating and soaking temperature to the rule kind of stove. This operation is the key blank is heated uniformly heated to a temperature suitable for processing. Because a great impact on the quality of the perforation, that is, when the temperature of the process piercing is an important condition affecting the quality, it is generally the temperature of the billet piercing working is to manipulate.
Pipe Stud End VS Pipe Cap
The stud end and pipe cap look similar sometimes. Both of them are two common fittings used at the end of industrial steel pipes. In some cases, they are regarded as one thing, and most of the time they can replace each other, that has the same function with them is the blind flange. If there are no special operation on the pipeline, then pipe cap or plug directly welded to the pipeline, if considering the future pipeline transformation or disassembly convenience requirements, then the blind flange will play a role.
Steel Pipe Cap, a pipe fitting welded to a pipe end or mounted on the external thread to seal a pipe, acting as a pipe plug. Ranges from connection types, the steel cap can be divided: butt weld cap, socket weld cap, threaded cap. The stud head is used for blocking the internal thread of the pipe end or the external thread of the flange. There are square tube plug, hexagonal tube plug, round plug.
Both Stub and cap are made by the same material and used for same applications. They are widely used in the petroleum, chemical, power, gas, metallurgy, shipbuilding and construction industries and they are made from high quality raw materials like carbon steel, alloy steel, stainless steel and available in a variety of sizes and designs according to ASME/ANSI B16.9. Any needs, call for us today!
Steel Pipe Cap, a pipe fitting welded to a pipe end or mounted on the external thread to seal a pipe, acting as a pipe plug. Ranges from connection types, the steel cap can be divided: butt weld cap, socket weld cap, threaded cap. The stud head is used for blocking the internal thread of the pipe end or the external thread of the flange. There are square tube plug, hexagonal tube plug, round plug.
Both Stub and cap are made by the same material and used for same applications. They are widely used in the petroleum, chemical, power, gas, metallurgy, shipbuilding and construction industries and they are made from high quality raw materials like carbon steel, alloy steel, stainless steel and available in a variety of sizes and designs according to ASME/ANSI B16.9. Any needs, call for us today!
2019年9月8日星期日
Characteristics of Outer Thickened Oil Casing
The outer thickened oil casing adopts the round pipe thread of the taper pipe, and is thickened through the joint to complete the joint and seal. It is one of the basic thread buckle types issued by the Petroleum Association. Its tooth shape is triangular, dome round bottom, the tooth angle is 60°, the thread taper is 1:16, and the tooth angle bisector is perpendicular to the axis. When the thread is tightened, the inner and outer snails.The side of the tooth has an interference fit and seal, which has simple processing, sealing with thread grease, some connection strength, and easy care and application on site. So what are the characteristics of the outer thickened oil casing? Here we briefly understand:
1. The joint strength is strengthened by the joint upsetting.
Without changing the thread form, the joint is subjected to the upsetting process to increase the joint size, which increases the joint strength and meets the requirements of the lower depth.
2. After the cooperation with the threaded grease, there is a gap of 0.076mm between the top of the sealed outer thickened oil sleeve and the bottom of the tooth. When the thread is tightened, the gap between the top of the head is full of thread grease, and the thread leakage is blocked after the thread grease is solidified. Thereby completing the sealing effect.
Externally thickened oil casings have an indelible contribution to the history of the petroleum industry. Following the development of the petroleum industry, the geological conditions are getting sour, and the outer thickened oil casing threads are constantly upgraded, gradually adapting to the requirements of unique formations.
http://www.xysteelpipe.com/info/Characteristics-of-Outer-Thickened-Oil-Casing-1503-1.htm
1. The joint strength is strengthened by the joint upsetting.
Without changing the thread form, the joint is subjected to the upsetting process to increase the joint size, which increases the joint strength and meets the requirements of the lower depth.
2. After the cooperation with the threaded grease, there is a gap of 0.076mm between the top of the sealed outer thickened oil sleeve and the bottom of the tooth. When the thread is tightened, the gap between the top of the head is full of thread grease, and the thread leakage is blocked after the thread grease is solidified. Thereby completing the sealing effect.
Externally thickened oil casings have an indelible contribution to the history of the petroleum industry. Following the development of the petroleum industry, the geological conditions are getting sour, and the outer thickened oil casing threads are constantly upgraded, gradually adapting to the requirements of unique formations.
http://www.xysteelpipe.com/info/Characteristics-of-Outer-Thickened-Oil-Casing-1503-1.htm
How to carry on the high precision inspection to the tube end wall thickness
After the steel tube is finished, there will be defects such as uneven wall thickness at both ends of the tube. Therefore, each steel tube must be cut off at both ends. Since the length of the tube end where each tube has defects is not equal, it is difficult to determine the specific cut length at the time of excision. Therefore, it is necessary to measure the wall thickness of the device.
The specific requirements for testing are as follows:
1. Continuous detection, while detecting the edge feed. Each steel pipe takes no more than 30 seconds;
2. The length of the test steel pipe is not less than 500mm;
3. After detecting the qualified position, the test stops, and the obvious mark is made on the outer surface of the steel pipe;
4. The quality of the cut steel pipe is within the tolerance of the national standard of the steel pipe, and the precision is 0.02mm;
5. Separate marking for the presence of local high points;
6. For the alarm of the steel pipe that exceeds the set range, the on-site personnel decide whether to release it.
http://www.xysteelpipe.com/info/How-to-carry-on-the-high-precision-inspection-to-the-tube-end-wall-thickness-1502-1.htm
The specific requirements for testing are as follows:
1. Continuous detection, while detecting the edge feed. Each steel pipe takes no more than 30 seconds;
2. The length of the test steel pipe is not less than 500mm;
3. After detecting the qualified position, the test stops, and the obvious mark is made on the outer surface of the steel pipe;
4. The quality of the cut steel pipe is within the tolerance of the national standard of the steel pipe, and the precision is 0.02mm;
5. Separate marking for the presence of local high points;
6. For the alarm of the steel pipe that exceeds the set range, the on-site personnel decide whether to release it.
http://www.xysteelpipe.com/info/How-to-carry-on-the-high-precision-inspection-to-the-tube-end-wall-thickness-1502-1.htm
2019年9月6日星期五
Difference between Seamless and ERW Stainless steel pipe
Today, Prime Steel will discuss about the key difference between Seamless and ERW Stainless Steel Pipe
What is the Raw material required for manufacturing Seamless & ERW Stainless steel Pipes?
Seamless Steel Pipe is made from a solid round steel ‘billet’ which is heated and pushed or pulled over a form until the steel is shaped into a hollow tube.
What is the Difference Between Seamless and ERW Stainless Steel Pipes?
Electric Resistance Welding (ERW) pipe is manufactured by rolling metal and then welding it longitudinally across its length. Seamless pipe is manufactured by extruding the metal to the desired length; therefore ERW pipe have a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length.
In Seamless pipe, there are no welding or joints and is manufactured from solid round billets. The seamless pipe is finished to dimensional and wall thickness specifications in sizes from 1/8 inch to 26 inch OD. Applicable in for High-pressure applications such as Hydrocarbon Industries & Refineries, Oil & Gas Exploration & Drilling, Oil & Gas Transportation and Air and Hydraulic cylinders, Bearings, Boilers, Automobiles etc.
ERW (Electric Resistance Welded) pipes are welded longitudinally, manufactured from Strip / Coil and can be manufactured upto 24” OD. ERW pipe cold formed from a ribbon of steel pulled through a series of rollers and formed into a tube which is fused through a electric charge. It is mainly used for low/ medium pressure applications such as transportation of water / oil.
What Technologies are used to manufacture Seamless & ERW Pipes?
Technologies for Production of Seamless & ERW Pipes “CPE” Technology” used for Seamless Pipes & Tubes Production up to 7-inches OD is the world renowned Technology. “Plug Mill” Technology used for Higher Dia. Seamless Pipes & Tubes Production from 7-inches to 14-inches,is the most reliable technology,in higher dia. Segment. High frequency Induction Welding Technology is used for ERW Pipes &Tubes upto 21-inchesOD.
How to Identify Seamless or ERW Stainless Steel pipes?
To identify that a pipe supplied is seamless or ERW, Simply read the stencil on the side of the pipe
If it is ASTM A53, Type S means seamless.
Type F is furnace but welded,
Type E is Electrical resist welded.
Thats how. It is the easiest way to identify wether pipe is seamless or ERW.
What is the Raw material required for manufacturing Seamless & ERW Stainless steel Pipes?
Seamless Steel Pipe is made from a solid round steel ‘billet’ which is heated and pushed or pulled over a form until the steel is shaped into a hollow tube.
What is the Difference Between Seamless and ERW Stainless Steel Pipes?
Electric Resistance Welding (ERW) pipe is manufactured by rolling metal and then welding it longitudinally across its length. Seamless pipe is manufactured by extruding the metal to the desired length; therefore ERW pipe have a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length.
In Seamless pipe, there are no welding or joints and is manufactured from solid round billets. The seamless pipe is finished to dimensional and wall thickness specifications in sizes from 1/8 inch to 26 inch OD. Applicable in for High-pressure applications such as Hydrocarbon Industries & Refineries, Oil & Gas Exploration & Drilling, Oil & Gas Transportation and Air and Hydraulic cylinders, Bearings, Boilers, Automobiles etc.
ERW (Electric Resistance Welded) pipes are welded longitudinally, manufactured from Strip / Coil and can be manufactured upto 24” OD. ERW pipe cold formed from a ribbon of steel pulled through a series of rollers and formed into a tube which is fused through a electric charge. It is mainly used for low/ medium pressure applications such as transportation of water / oil.
What Technologies are used to manufacture Seamless & ERW Pipes?
Technologies for Production of Seamless & ERW Pipes “CPE” Technology” used for Seamless Pipes & Tubes Production up to 7-inches OD is the world renowned Technology. “Plug Mill” Technology used for Higher Dia. Seamless Pipes & Tubes Production from 7-inches to 14-inches,is the most reliable technology,in higher dia. Segment. High frequency Induction Welding Technology is used for ERW Pipes &Tubes upto 21-inchesOD.
How to Identify Seamless or ERW Stainless Steel pipes?
To identify that a pipe supplied is seamless or ERW, Simply read the stencil on the side of the pipe
If it is ASTM A53, Type S means seamless.
Type F is furnace but welded,
Type E is Electrical resist welded.
Thats how. It is the easiest way to identify wether pipe is seamless or ERW.
2019年9月5日星期四
Low,Medium and High Carbon Steel
The world of carbon steels can be challenging to wrap your head around. There are many different options to choose from, and each type of steel has different benefits. The main differentiating factor is the amount of carbon that is mixed with iron during production. Other materials, mainly metals, can be added to change the physical properties. Notably, chromium is added to form stainless steel, while other big picture, there are three distinctions between carbon steels: low, medium, and high.
Low carbon steel
Low carbon steels such as 302, 304 or 316 grades of stainless are typically used in applications which require high degrees of corrosion resistance but do not require a hardened surface. The carbon content of these steels typically range between 0.03-0.08%, and consumers typically use these grades of stainless (often without thinking about it) in kitchen equipment, silverware or almost any grade of un-plated steel used in food preparation. It’s great because it can survive the dishwasher without rusting, but it cannot be case hardened due to the very low carbon content.
While it can be used to make linear shafting, it isn’t suitable for loaded ball contact. So if a linear ball bushing were to be used on a soft 304 stainless steel shaft, for example, the balls in the bearing would quickly impact the shaft surface, resulting in visible ball tracking on its surface and a drastic reduction in both bearing and shaft life. It can, however, be used in conjunction with polymer, plain-style bearings which provide great options for both corrosion resistance and self-lubrication. For the right applications, a 300 series stainless steel linear shaft presents a great option for withstanding tough environmental conditions!
Medium carbon steel
Medium carbon steels include grades with carbon contents ranging from 0.25% to 0.60% of the steel mass. Medium carbon grades are typically employed in conjunction with alloys such as chromium, nickel and molybdenum to produce high strength, wear resistance and toughness. Products using medium grades of carbon steel include gears, axles, studs and other machine components that require optimal combinations of strength and toughness.
Medium carbon steels have good machining characteristics, and one of the more popular grades used in machined steel product is AISI 1045. AISI 1045 can also be hardened by heating the material too approximately 820-850C (1508 -1562 F) and held until the material reaches a uniform temperature. It should be soaked for one hour per 25 mm section of material and subsequently cooled in still air.
High carbon steel
High carbon steels are those with carbon contents between 0.60% and 1.4% of the overall weight. The alloys in this particular category constitute the strongest and hardest within the three groups, but they are also the least ductile. These steels are used in a range of different mechanical, cutting and bearing applications as it can be hardened through heat treating and tempering. Additional alloys can be added to this steel category in order to generate different characteristics. Chromium and Manganese, for example, are used in the composition of 52100 steel and aid in the hardening process while enhancing the steel’s resistance to corrosion. Since 52100 is one of the steel grades frequently used to manufacture linear shafting, precise control of the case depth can be critical to generate a shaft with both a hardened surface (for loaded ball contact) and an un-hardened inner core which prevents the shaft from becoming brittle.
Steel alloys are given designators by organizations such as the American Iron and Steel Institute (AISI) and the American Society for Testing and Materials (ASTM) for easier classification and identification. AISI typically follows a four digit system, where the first two digits indicate the alloy, and the second two digits denote the carbon content. ASTM uses an “A” to denote ferrous materials, followed by an arbitrarily assigned number for each alloy.
Regardless of the system used, this standardization allows cross talk between designers, engineers, and builders to ensure the proper material is being selected and used in engineering projects. It also makes looking up physical properties of alloys very easy, as a simple search with the identification number produces the correct information.
Low carbon steel
Low carbon steels such as 302, 304 or 316 grades of stainless are typically used in applications which require high degrees of corrosion resistance but do not require a hardened surface. The carbon content of these steels typically range between 0.03-0.08%, and consumers typically use these grades of stainless (often without thinking about it) in kitchen equipment, silverware or almost any grade of un-plated steel used in food preparation. It’s great because it can survive the dishwasher without rusting, but it cannot be case hardened due to the very low carbon content.
While it can be used to make linear shafting, it isn’t suitable for loaded ball contact. So if a linear ball bushing were to be used on a soft 304 stainless steel shaft, for example, the balls in the bearing would quickly impact the shaft surface, resulting in visible ball tracking on its surface and a drastic reduction in both bearing and shaft life. It can, however, be used in conjunction with polymer, plain-style bearings which provide great options for both corrosion resistance and self-lubrication. For the right applications, a 300 series stainless steel linear shaft presents a great option for withstanding tough environmental conditions!
Medium carbon steel
Medium carbon steels include grades with carbon contents ranging from 0.25% to 0.60% of the steel mass. Medium carbon grades are typically employed in conjunction with alloys such as chromium, nickel and molybdenum to produce high strength, wear resistance and toughness. Products using medium grades of carbon steel include gears, axles, studs and other machine components that require optimal combinations of strength and toughness.
Medium carbon steels have good machining characteristics, and one of the more popular grades used in machined steel product is AISI 1045. AISI 1045 can also be hardened by heating the material too approximately 820-850C (1508 -1562 F) and held until the material reaches a uniform temperature. It should be soaked for one hour per 25 mm section of material and subsequently cooled in still air.
High carbon steel
High carbon steels are those with carbon contents between 0.60% and 1.4% of the overall weight. The alloys in this particular category constitute the strongest and hardest within the three groups, but they are also the least ductile. These steels are used in a range of different mechanical, cutting and bearing applications as it can be hardened through heat treating and tempering. Additional alloys can be added to this steel category in order to generate different characteristics. Chromium and Manganese, for example, are used in the composition of 52100 steel and aid in the hardening process while enhancing the steel’s resistance to corrosion. Since 52100 is one of the steel grades frequently used to manufacture linear shafting, precise control of the case depth can be critical to generate a shaft with both a hardened surface (for loaded ball contact) and an un-hardened inner core which prevents the shaft from becoming brittle.
Steel alloys are given designators by organizations such as the American Iron and Steel Institute (AISI) and the American Society for Testing and Materials (ASTM) for easier classification and identification. AISI typically follows a four digit system, where the first two digits indicate the alloy, and the second two digits denote the carbon content. ASTM uses an “A” to denote ferrous materials, followed by an arbitrarily assigned number for each alloy.
Regardless of the system used, this standardization allows cross talk between designers, engineers, and builders to ensure the proper material is being selected and used in engineering projects. It also makes looking up physical properties of alloys very easy, as a simple search with the identification number produces the correct information.
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