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.
2019年9月29日星期日
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.
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