1. Forged steel: a pressure processing method that uses the reciprocating impact force of a forging hammer or the pressure of a press to change the blank into the shape and size we need.
2. Extrusion: It is the processing method in which the steel puts the metal in a closed extruding chamber and applies pressure at one end to extrude the metal from the specified die hole to obtain a finished product of the same shape and size. Mostly used to produce non-ferrous metal steel.
3. Rolling: Pressing the steel metal billet through a pair of rotating rollers (various shapes), the compression of the roller reduces the cross-section of the material and increases the length.
4. Pulling steel: pulling the rolled metal blanks (types, tubes, products, etc.) through the die holes, this method is mostly used for cold processing.
http://www.xysteelpipe.com/info/Straight-seam-steel-tube-processing-technology-1701-1.htm
2020年7月21日星期二
2020年6月21日星期日
Safety management and characteristics of penetration test
Safety management
The flaw detection agents used in penetrant testing are almost all oily flammable substances. Special attention should be paid to fire prevention. The flaw detection agents are generally non-toxic or low-toxic, and people will also feel uncomfortable when touching. In sealed containers or indoors, adequate ventilation is required.
Features
1) Applicable to any kind of materials except loose porous materials, suitable for surface defect detection of non-ferromagnetic materials.
2) For work-pieces whose structure, shape and size are not conducive to magnetization, infiltration can be used.
3) Unable to detect buried defects and closed defects.
4) There are defects in several directions at the same time, only one flaw detection operation is needed for penetrant testing, and magnetization testing needs to be performed in at least two directions.
http://www.xysteelpipe.com/info/Safety-management-and-characteristics-of-penetration-test-1694-1.htm
The flaw detection agents used in penetrant testing are almost all oily flammable substances. Special attention should be paid to fire prevention. The flaw detection agents are generally non-toxic or low-toxic, and people will also feel uncomfortable when touching. In sealed containers or indoors, adequate ventilation is required.
Features
1) Applicable to any kind of materials except loose porous materials, suitable for surface defect detection of non-ferromagnetic materials.
2) For work-pieces whose structure, shape and size are not conducive to magnetization, infiltration can be used.
3) Unable to detect buried defects and closed defects.
4) There are defects in several directions at the same time, only one flaw detection operation is needed for penetrant testing, and magnetization testing needs to be performed in at least two directions.
http://www.xysteelpipe.com/info/Safety-management-and-characteristics-of-penetration-test-1694-1.htm
Large Diameter J55 Long Round Buckle Oil Casing Pipe
The main standard of large-diameter J55 oil casing pipe is API 5L, the outer diameter of large-diameter oil casing is expressed in inches, and 1b/ft is the unit of weight. The oil casing adopts different materials according to different strengths and well depths and conditions. The main materials are K55 oil casing, J55 oil casing, N80, P110 oil casing. The problems that often occur in large-diameter oil casings are broken buckles, damaged wire buckles, black buckles, pipe folds, and casing brittle fractures. "P" for large-diameter oil casing represents flat end, "L" represents long round buckle, "B" represents partial trapezoid buckle, and "S" represents short round buckle. The length of J55 oil casing is within 12 meters, and it can be processed according to the needs of customers.
Long round buckle oil casing, abbreviated as Ltc. in English, is a widely used buckle shape of oil casing. The thread shape at both ends of the pipe body is like an oblong shape, so it is called long round buckle oil casing.
There are three specified lengths of API long round buckle oil casing: R-1 is 4.88～7.62m, R-2 is 7.62～10.36m, R-3 is 10.36m to longer. The main materials include J55, K55, N80, L80, C90, T95, P110, Q125, V150. Among them, the H-40 steel grade is the lowest, and the P-110 steel grade has the highest strength. According to the different steel grades, the color of the casing is also different. The commonly used steel grades are J-55 painted green, N-80 painted red, and P-110 painted white.The mechanical properties of the three long round buckle oil casings are mainly hydrostatic pressure test, flattening test, sulfide stress corrosion cracking test, hardness test, tensile test and transverse impact test. Where the geological conditions are complex, the casing is also required to have anti-collapse properties. The oblong thread has the advantages of easy processing, good sealing, certain connection strength, simple on-site maintenance and use, and low price. It is widely used in casing connection.
http://www.xysteelpipe.com/info/Large-Diameter-J55-Long-Round-Buckle-Oil-Casing-Pipe-1693-1.htm
Long round buckle oil casing, abbreviated as Ltc. in English, is a widely used buckle shape of oil casing. The thread shape at both ends of the pipe body is like an oblong shape, so it is called long round buckle oil casing.
There are three specified lengths of API long round buckle oil casing: R-1 is 4.88～7.62m, R-2 is 7.62～10.36m, R-3 is 10.36m to longer. The main materials include J55, K55, N80, L80, C90, T95, P110, Q125, V150. Among them, the H-40 steel grade is the lowest, and the P-110 steel grade has the highest strength. According to the different steel grades, the color of the casing is also different. The commonly used steel grades are J-55 painted green, N-80 painted red, and P-110 painted white.The mechanical properties of the three long round buckle oil casings are mainly hydrostatic pressure test, flattening test, sulfide stress corrosion cracking test, hardness test, tensile test and transverse impact test. Where the geological conditions are complex, the casing is also required to have anti-collapse properties. The oblong thread has the advantages of easy processing, good sealing, certain connection strength, simple on-site maintenance and use, and low price. It is widely used in casing connection.
http://www.xysteelpipe.com/info/Large-Diameter-J55-Long-Round-Buckle-Oil-Casing-Pipe-1693-1.htm
Key points of processing technology for large diameter straight seam steel pipe
Rebar thread processing
1. The thread head, tooth shape and pitch of the processed steel thread are consistent with the tooth shape and pitch of the connecting sleeve, and they are qualified by the matching gauge.
2. When processing steel thread, water-soluble cutting lubricant should be used; when the temperature is lower than 0℃, sodium nitrite should be mixed, and engine oil should not be used as lubricating fluid or threaded without lubricating fluid.
3. The operator should check the appearance of the steel wire head one by one and make the operator mark.
4. After the self-inspection of the steel wire head, 10% of each specification should be randomly checked, and no less than 10, if one is not qualified, the batch of processed products should be fully inspected. The unqualified silk heads should be reprocessed and used after passing the inspection again.
5. The silk heads that have passed the inspection shall be protected, put on protective caps, and be neatly classified according to specifications for use.
http://www.xysteelpipe.com/info/Key-points-of-processing-technology-for-large-diameter-straight-seam-steel-pipe-1692-1.htm
1. The thread head, tooth shape and pitch of the processed steel thread are consistent with the tooth shape and pitch of the connecting sleeve, and they are qualified by the matching gauge.
2. When processing steel thread, water-soluble cutting lubricant should be used; when the temperature is lower than 0℃, sodium nitrite should be mixed, and engine oil should not be used as lubricating fluid or threaded without lubricating fluid.
3. The operator should check the appearance of the steel wire head one by one and make the operator mark.
4. After the self-inspection of the steel wire head, 10% of each specification should be randomly checked, and no less than 10, if one is not qualified, the batch of processed products should be fully inspected. The unqualified silk heads should be reprocessed and used after passing the inspection again.
5. The silk heads that have passed the inspection shall be protected, put on protective caps, and be neatly classified according to specifications for use.
http://www.xysteelpipe.com/info/Key-points-of-processing-technology-for-large-diameter-straight-seam-steel-pipe-1692-1.htm
2020年6月18日星期四
Anticorrosive Spiral Steel Tube
The anticorrosive spiral steel pipe(SSAW) is mainly used for anticorrosion of the external walls of buried or underwater steel oil, gas, water, and heating pipelines, and is also suitable for various types of steel structures, docks, ships, sluices, gas storage tanks, and oil refinery plant equipment. Anti-corrosion and waterproof and anti-leakage for concrete pipes, sewage tanks, roof waterproof layer, toilets, basements and other concrete structures.
Anticorrosive medium of anticorrosive spiral steel pipe:
There are many types of corrosion media in IPN8710 anticorrosive spiral steel pipe, including acid, alkali, salt, oxidant and water vapor. The coating must be chemically inert and resistant to acid, alkali and salt corrosion. , Tough and plump.
1. IPN8710 anticorrosive spiral steel pipe primer: It is composed of polyurethane polyethylene, modified epoxy resin, non-toxic anti-rust pigment filler, additives, etc. It is cured at room temperature to form an interpenetrating network, the coating film structure is dense, acid, alkali, Salt, excellent anti-rust performance, strong adhesion.
2. IPN8710 anticorrosive spiral steel pipe topcoat: It is composed of epoxy resin, rubber resin modified, non-toxic antirust paint, additives, etc. Excellent chemical resistance, non-toxic, anti-microbial erosion.
Four advantages of anti-corrosion steel pipes in practical applications:
1. The construction is simple and the steps are quick, and the construction can be carried out in the factory and on site. Compared with old steel pipes, the construction of anti-corrosion steel pipes is very simple. No need for large equipment and space. On-site operation is very suitable. Anti-corrosion treatment can be carried out at the same time during on-site construction.
2. In the case of combining the quality and service life of the steel pipe, the service life and investment can reach a reasonable ratio, which is more economical and more applicable than the old pipeline, which is also an important deciding factor for people to buy.
3. Long service life, ordinary steel tubes have a certain service life. After the anticorrosion treatment of common materials, its service life can be as long as 20-30 years or even longer, thereby saving the cost of replacement and other uses.
4. The design of anti-corrosion steel pipes is centered on environmental protection. In today's environment-friendly environment, this design is more in line with the needs of the times. In the future, the environmental protection requirements for the pipelines that transport fluids will become increasingly strict. Products that cannot be developed on behalf of the environment will be eliminated.
Hardness index of anticorrosive spiral steel pipe:
The ability of a metal material to resist a hard object from crushing a surface is called hardness. According to different test methods and application scope, hardness can be divided into Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, micro hardness and high temperature hardness. Brinell, Rockwell, and Vickers hardness are commonly used for corrosion-resistant spiral steel pipes.
A. Brinell hardness (HB Use a certain diameter steel ball or cemented carbide ball, press into the sample surface with the specified test force (F), remove the test force after the specified holding time, and measure the indentation diameter of the sample surface (L) The Brinell hardness value is the quotient obtained by dividing the test force by the indented spherical surface area.
B. Rockwell hardness (HK) The Rockwell hardness test is the same as the Brinell hardness test, and is an indentation test method. The difference is that it measures the depth of the indentation. That is, under the effect of the initial Yong test force (Fo) and the total test force (F), press the indenter (cone or steel ball of the steel plant) into the surface of the sample, and after the specified holding time, remove the main For the test force, use the measured residual indentation depth increment (e) to calculate the hardness value.
C. Vickers hardness (HV) The Vickers hardness test is also an indentation test method, which is to press a regular quadrangular pyramid diamond indenter with an opposing angle of 1360 into the test surface with a selected test force (F). After the specified holding time, remove the test force and measure the length of the two diagonal lines of the indentation. The Vickers hardness value is the quotient obtained by dividing the test force by the indentation surface area. The calculation formula is: HV--Vickers hardness symbol, N/mm2 (MPa); F--test force, N; d--pressure The arithmetic mean of the two diagonals of the mark, mm. The test force F used for Vickers hardness is 5 (49.03), 10 (98.07), 20 (196.1), 30 (294.2), 50(490.3), 100 (980.7) Kgf (N) and other six levels, the measurable hardness degree value range is 5 ~ 1000HV.
http://www.xysteelpipe.com/info/Anticorrosive-Spiral-Steel-Tube-1691-1.htm
Anticorrosive medium of anticorrosive spiral steel pipe:
There are many types of corrosion media in IPN8710 anticorrosive spiral steel pipe, including acid, alkali, salt, oxidant and water vapor. The coating must be chemically inert and resistant to acid, alkali and salt corrosion. , Tough and plump.
1. IPN8710 anticorrosive spiral steel pipe primer: It is composed of polyurethane polyethylene, modified epoxy resin, non-toxic anti-rust pigment filler, additives, etc. It is cured at room temperature to form an interpenetrating network, the coating film structure is dense, acid, alkali, Salt, excellent anti-rust performance, strong adhesion.
2. IPN8710 anticorrosive spiral steel pipe topcoat: It is composed of epoxy resin, rubber resin modified, non-toxic antirust paint, additives, etc. Excellent chemical resistance, non-toxic, anti-microbial erosion.
Four advantages of anti-corrosion steel pipes in practical applications:
1. The construction is simple and the steps are quick, and the construction can be carried out in the factory and on site. Compared with old steel pipes, the construction of anti-corrosion steel pipes is very simple. No need for large equipment and space. On-site operation is very suitable. Anti-corrosion treatment can be carried out at the same time during on-site construction.
2. In the case of combining the quality and service life of the steel pipe, the service life and investment can reach a reasonable ratio, which is more economical and more applicable than the old pipeline, which is also an important deciding factor for people to buy.
3. Long service life, ordinary steel tubes have a certain service life. After the anticorrosion treatment of common materials, its service life can be as long as 20-30 years or even longer, thereby saving the cost of replacement and other uses.
4. The design of anti-corrosion steel pipes is centered on environmental protection. In today's environment-friendly environment, this design is more in line with the needs of the times. In the future, the environmental protection requirements for the pipelines that transport fluids will become increasingly strict. Products that cannot be developed on behalf of the environment will be eliminated.
Hardness index of anticorrosive spiral steel pipe:
The ability of a metal material to resist a hard object from crushing a surface is called hardness. According to different test methods and application scope, hardness can be divided into Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, micro hardness and high temperature hardness. Brinell, Rockwell, and Vickers hardness are commonly used for corrosion-resistant spiral steel pipes.
A. Brinell hardness (HB Use a certain diameter steel ball or cemented carbide ball, press into the sample surface with the specified test force (F), remove the test force after the specified holding time, and measure the indentation diameter of the sample surface (L) The Brinell hardness value is the quotient obtained by dividing the test force by the indented spherical surface area.
B. Rockwell hardness (HK) The Rockwell hardness test is the same as the Brinell hardness test, and is an indentation test method. The difference is that it measures the depth of the indentation. That is, under the effect of the initial Yong test force (Fo) and the total test force (F), press the indenter (cone or steel ball of the steel plant) into the surface of the sample, and after the specified holding time, remove the main For the test force, use the measured residual indentation depth increment (e) to calculate the hardness value.
C. Vickers hardness (HV) The Vickers hardness test is also an indentation test method, which is to press a regular quadrangular pyramid diamond indenter with an opposing angle of 1360 into the test surface with a selected test force (F). After the specified holding time, remove the test force and measure the length of the two diagonal lines of the indentation. The Vickers hardness value is the quotient obtained by dividing the test force by the indentation surface area. The calculation formula is: HV--Vickers hardness symbol, N/mm2 (MPa); F--test force, N; d--pressure The arithmetic mean of the two diagonals of the mark, mm. The test force F used for Vickers hardness is 5 (49.03), 10 (98.07), 20 (196.1), 30 (294.2), 50(490.3), 100 (980.7) Kgf (N) and other six levels, the measurable hardness degree value range is 5 ~ 1000HV.
http://www.xysteelpipe.com/info/Anticorrosive-Spiral-Steel-Tube-1691-1.htm
2020年5月7日星期四
The corrosion protection of steel pipes is closely related to the service life
The anticorrosion of buried steel pipes is the key procedure to ensure and prolong their service life. In order to ensure that the anti-corrosive insulation layer is firmly combined with the pipe wall, the most important thing is the derusting of the pipeline.
Generally, the rust on the surface of the American standard steel pipe can be divided into floating rust, medium rust and heavy rust according to the delivery time, storage and transportation conditions, and the degree of climate humidity.
Floating rust: Generally, when there is a short delivery date, and there is a small amount of thin rust on the surface of the tube when it is not stored in the open air, the metal luster can be exposed by manual operations such as wire brush, sandpaper and cotton yarn.
Medium rust and heavy rust: When the factory date is long and the open storage or multiple transfers and transportation are long, the surface of the tube is oxidized and rusted, and the rust spots are heavy. In severe cases, the scale is peeled off.
Severely corroded pipelines are not suitable for water delivery systems. For medium-rust pipes and large batches, rust removal machines or mechanical sandblasting can be used for mechanical derusting, which can improve labor efficiency and reduce pollution to people and air. .
When high corrosion resistance is required or the inner and outer walls of the pipe have been corroded, the chemical derusting method can be used to effectively remove the oxides on the inner and outer surfaces of the pipe.
No matter which method is used to remove rust, the anticorrosion layer should be treated immediately after the rust is removed to avoid being oxidized and corroded by the air again.
http://www.xysteelpipe.com/info/The-corrosion-protection-of-steel-pipes-is-closely-related-to-the-service-life-1667-1.htm
Generally, the rust on the surface of the American standard steel pipe can be divided into floating rust, medium rust and heavy rust according to the delivery time, storage and transportation conditions, and the degree of climate humidity.
Floating rust: Generally, when there is a short delivery date, and there is a small amount of thin rust on the surface of the tube when it is not stored in the open air, the metal luster can be exposed by manual operations such as wire brush, sandpaper and cotton yarn.
Medium rust and heavy rust: When the factory date is long and the open storage or multiple transfers and transportation are long, the surface of the tube is oxidized and rusted, and the rust spots are heavy. In severe cases, the scale is peeled off.
Severely corroded pipelines are not suitable for water delivery systems. For medium-rust pipes and large batches, rust removal machines or mechanical sandblasting can be used for mechanical derusting, which can improve labor efficiency and reduce pollution to people and air. .
When high corrosion resistance is required or the inner and outer walls of the pipe have been corroded, the chemical derusting method can be used to effectively remove the oxides on the inner and outer surfaces of the pipe.
No matter which method is used to remove rust, the anticorrosion layer should be treated immediately after the rust is removed to avoid being oxidized and corroded by the air again.
http://www.xysteelpipe.com/info/The-corrosion-protection-of-steel-pipes-is-closely-related-to-the-service-life-1667-1.htm
2020年5月6日星期三
Production of cold-drawn precision seamless steel tube
1. Hair management. The wall thickness of the capillary should be uniform, with fewer defects on the inner and outer surfaces. Equipment for polishing external surfaces and cleaning internal hole defects shall be provided.
2. Review. In the production of cold drawn precision seamless steel tubes, compared with ordinary cold drawn steel tubes, hot rolling capillary pickling and re-inspection processes are added. This is to ensure that there are no defects such as folds and cracks on the outer surface of the capillary, and to eliminate defects such as folds, severe marking and linen surface on the inner surface of the capillary.
3. Tools. The surface finish of the tools used in the production of cold-drawn precision seamless steel tubes should be controlled. At the same time, the head or mould is prevented from being stuck during the drawing process.
4. The production process of cold-rolled seamless steel pipe is generally more complicated than that of hot-rolling. If the surface does not respond to cracks, the round pipe is cut and cut into a billet with a length of about one meter. Annealing is a very important part in the production process of cold drawn steel pipes. The quality of annealing not only affects the performance of the steel pipe, but also affects the removal of scale.
5. In the pickling process of precision seamless steel tubes, black slag is easily formed, and in subsequent production, black spots will form on the surface. Black residue is easily soluble in hydrochloric acid. In order to prevent the formation of black spots, hydrochloric acid should be added to the acid tank.
6. Resin should be used as lubricant. Compared with phosphating and lubrication, lubrication has obvious differences. The drawn steel pipe has the characteristics of an iron matrix, which not only has high finish, but also has the beautiful appearance of cold-rolled steel pipe.
2. Review. In the production of cold drawn precision seamless steel tubes, compared with ordinary cold drawn steel tubes, hot rolling capillary pickling and re-inspection processes are added. This is to ensure that there are no defects such as folds and cracks on the outer surface of the capillary, and to eliminate defects such as folds, severe marking and linen surface on the inner surface of the capillary.
3. Tools. The surface finish of the tools used in the production of cold-drawn precision seamless steel tubes should be controlled. At the same time, the head or mould is prevented from being stuck during the drawing process.
4. The production process of cold-rolled seamless steel pipe is generally more complicated than that of hot-rolling. If the surface does not respond to cracks, the round pipe is cut and cut into a billet with a length of about one meter. Annealing is a very important part in the production process of cold drawn steel pipes. The quality of annealing not only affects the performance of the steel pipe, but also affects the removal of scale.
5. In the pickling process of precision seamless steel tubes, black slag is easily formed, and in subsequent production, black spots will form on the surface. Black residue is easily soluble in hydrochloric acid. In order to prevent the formation of black spots, hydrochloric acid should be added to the acid tank.
6. Resin should be used as lubricant. Compared with phosphating and lubrication, lubrication has obvious differences. The drawn steel pipe has the characteristics of an iron matrix, which not only has high finish, but also has the beautiful appearance of cold-rolled steel pipe.
Common Materials of ERW Welded Pipe
Common materials for welded pipes are: Q235A, Q235C, Q235B, 16Mn, 20 #, Q345, L245, L290, X42, X46, X60, X80, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc.
The blank used for welded steel pipe is steel plate or strip steel, which is divided into furnace welded pipe, electric resistance welded pipe and automatic arc welded pipe due to different welding processes. Because of its different welding forms, it is divided into two types: straight seam welded pipe and spiral welded pipe. Because of its end shape, it is divided into round welded pipe and special-shaped (square, flat, etc.) welded pipe. Welded pipes are divided into the following varieties due to their different materials and uses:
GB / T3091-2008 (welded steel pipe for low-pressure fluid transportation): mainly used for conveying water, gas, air, oil and heating hot water or steam and other generally low-pressure fluid and other use pipes. Its representative material is: Q235A grade steel.
GB / T14291-2006 (Welding Steel Pipe for Mine Fluid Transportation): Mainly used for straight seam welded steel pipes for mine pressure, drainage and shaft gas discharge. Its representative material is Q235A, B grade steel.
GB / T12770-2002 (stainless steel welded steel pipe for mechanical structure): mainly used for machinery, automobiles, bicycles, furniture, hotel and restaurant decoration and other mechanical parts and structural parts. Its representative materials are 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb and so on.
GB / T12771-1991 (stainless steel welded steel pipe for fluid transportation): mainly used to transport low-pressure corrosive media. Representative materials are 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, 0017Cr17Ni14Mo2, etc.
In addition, welded stainless steel pipes for decoration (GB / T 18705-2002), welded stainless steel pipes for building decoration (JG / T 3030-1995), and welded steel pipes for heat exchangers (YB4103-2000).
The blank used for welded steel pipe is steel plate or strip steel, which is divided into furnace welded pipe, electric resistance welded pipe and automatic arc welded pipe due to different welding processes. Because of its different welding forms, it is divided into two types: straight seam welded pipe and spiral welded pipe. Because of its end shape, it is divided into round welded pipe and special-shaped (square, flat, etc.) welded pipe. Welded pipes are divided into the following varieties due to their different materials and uses:
GB / T3091-2008 (welded steel pipe for low-pressure fluid transportation): mainly used for conveying water, gas, air, oil and heating hot water or steam and other generally low-pressure fluid and other use pipes. Its representative material is: Q235A grade steel.
GB / T14291-2006 (Welding Steel Pipe for Mine Fluid Transportation): Mainly used for straight seam welded steel pipes for mine pressure, drainage and shaft gas discharge. Its representative material is Q235A, B grade steel.
GB / T12770-2002 (stainless steel welded steel pipe for mechanical structure): mainly used for machinery, automobiles, bicycles, furniture, hotel and restaurant decoration and other mechanical parts and structural parts. Its representative materials are 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb and so on.
GB / T12771-1991 (stainless steel welded steel pipe for fluid transportation): mainly used to transport low-pressure corrosive media. Representative materials are 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, 0017Cr17Ni14Mo2, etc.
In addition, welded stainless steel pipes for decoration (GB / T 18705-2002), welded stainless steel pipes for building decoration (JG / T 3030-1995), and welded steel pipes for heat exchangers (YB4103-2000).
Fire prevention measures for seamless steel tube
At present, seamless steel tube construction is increasing, especially in some buildings, the use of seamless steel tube materials is more widespread. Once a fire accident occurs in a building, the fire cannot be extinguished in a short period of time. This requires us to design the building to provide fire protection to the building materials to enhance their fire resistance, and to formulate the necessary emergency plan inside the building to reduce Casualties and property damage. So, what are the fire protection measures for seamless steel tubes?
1. Outer cladding. It is to add an outer cladding on the surface of the seamless steel tube, which can be cast-in-place or sprayed. The cast-in-situ molded solid concrete outer cladding is usually strengthened with steel wire mesh or steel bars to limit shrinkage cracks and ensure the strength of the shell. The spraying method can apply a sand pump to the surface of the seamless steel pipe at the construction site to form a layer. The sand pump can be lime cement or gypsum mortar, or can be mixed with perlite or asbestos. At the same time, the outer cladding can also be made of perlite, asbestos, gypsum or asbestos cement, and light concrete into prefabricated panels, which are fixed on seamless steel pipes with adhesives, nails, and bolts.
2. Fill with water. Straight seam steel pipes are steel pipes with welds parallel to the longitudinal direction of the steel pipe. Usually divided into metric welded steel pipes, welded thin-walled pipes, transformer cooling oil pipes, etc. Straight seam welded pipe production process is simple, high production efficiency, low cost and rapid development. The strength of spiral welded pipe is generally higher than that of straight seam welded pipe. It is possible to use narrow blanks to produce welded pipes with larger diameters. It is also possible to use the same width of blanks to produce welded pipes with different pipe diameters. Filling the hollow seamless steel pipe with water is an effective protective measure against fire. This method can keep the seamless steel pipe at a low temperature in the fire, water circulates in the seamless steel pipe, and absorbs the heat of the material itself. The heated water can be recirculated after cooling, or cool water can be introduced through pipes to replace the heated water.
3. Shield. Precision steel pipe is a kind of high-precision steel pipe material processed by cold drawing or hot rolling. Because the inner and outer walls of the precision steel pipe have no oxide layer, withstand high pressure without leakage, high precision, high finish, cold bending without deformation, flaring, flattening and no crack, etc., it is mainly used to produce products for pneumatic or hydraulic components, such as cylinder Cylinders can be seamless or welded. The seamless steel pipe is installed in the wall or ceiling made of refractory materials, or the components are hidden in the gap between the two walls. As long as a little refractory material is added or not added, the purpose of fire prevention can be achieved. This is a very economical method of fire prevention.
4. Expansion materials. The use of seamless steel tube fireproof coating components, this method has the advantages of good fire insulation performance, construction is not limited by the geometric shape of the seamless steel tube, etc., generally do not add auxiliary facilities, and the coating quality is light, and also has a certain decorative effect, It belongs to modern advanced fire prevention technical measures.
http://www.xysteelpipe.com/info/Fire-prevention-measures-for-seamless-steel-tube-1666-1.htm
1. Outer cladding. It is to add an outer cladding on the surface of the seamless steel tube, which can be cast-in-place or sprayed. The cast-in-situ molded solid concrete outer cladding is usually strengthened with steel wire mesh or steel bars to limit shrinkage cracks and ensure the strength of the shell. The spraying method can apply a sand pump to the surface of the seamless steel pipe at the construction site to form a layer. The sand pump can be lime cement or gypsum mortar, or can be mixed with perlite or asbestos. At the same time, the outer cladding can also be made of perlite, asbestos, gypsum or asbestos cement, and light concrete into prefabricated panels, which are fixed on seamless steel pipes with adhesives, nails, and bolts.
2. Fill with water. Straight seam steel pipes are steel pipes with welds parallel to the longitudinal direction of the steel pipe. Usually divided into metric welded steel pipes, welded thin-walled pipes, transformer cooling oil pipes, etc. Straight seam welded pipe production process is simple, high production efficiency, low cost and rapid development. The strength of spiral welded pipe is generally higher than that of straight seam welded pipe. It is possible to use narrow blanks to produce welded pipes with larger diameters. It is also possible to use the same width of blanks to produce welded pipes with different pipe diameters. Filling the hollow seamless steel pipe with water is an effective protective measure against fire. This method can keep the seamless steel pipe at a low temperature in the fire, water circulates in the seamless steel pipe, and absorbs the heat of the material itself. The heated water can be recirculated after cooling, or cool water can be introduced through pipes to replace the heated water.
3. Shield. Precision steel pipe is a kind of high-precision steel pipe material processed by cold drawing or hot rolling. Because the inner and outer walls of the precision steel pipe have no oxide layer, withstand high pressure without leakage, high precision, high finish, cold bending without deformation, flaring, flattening and no crack, etc., it is mainly used to produce products for pneumatic or hydraulic components, such as cylinder Cylinders can be seamless or welded. The seamless steel pipe is installed in the wall or ceiling made of refractory materials, or the components are hidden in the gap between the two walls. As long as a little refractory material is added or not added, the purpose of fire prevention can be achieved. This is a very economical method of fire prevention.
4. Expansion materials. The use of seamless steel tube fireproof coating components, this method has the advantages of good fire insulation performance, construction is not limited by the geometric shape of the seamless steel tube, etc., generally do not add auxiliary facilities, and the coating quality is light, and also has a certain decorative effect, It belongs to modern advanced fire prevention technical measures.
http://www.xysteelpipe.com/info/Fire-prevention-measures-for-seamless-steel-tube-1666-1.htm
2020年5月5日星期二
Process characteristics of spiral steel tube
Spiral steel pipe is mainly used in water engineering, petrochemical industry, chemical industry, power industry, agricultural irrigation, and urban construction. It is one of the twenty key products developed.
For liquid transportation: water supply and drainage.
For gas transportation: coal gas, steam, liquefied petroleum gas.
For structural use: for piling pipes and bridges; for docks, roads, and building structures.
Main technical characteristics of spiral steel pipe:
1. During the forming process, the steel plate deforms uniformly, the residual stress is small, and the surface is not scratched. The processed spiral steel pipe has more flexibility in the range of diameter and wall thickness. Especially in the production of small and medium-diameter thick-walled pipes, it has advantages that are unmatched by other processes, and can meet the user's more requirements on spiral steel pipe specifications .
2. Adopting advanced double-sided submerged arc welding technology, welding can be achieved in a good position, which is not prone to defects such as misalignment, welding deviation and under-welding, and it is easy to control welding quality.
3, 100% quality inspection of steel pipes, so that the entire process of steel pipe production under effective detection and monitoring, effectively guarantee product quality.
4. All the equipment of the whole production line has the function of networking with computer data acquisition system, real-time data transmission, and the central control room controls the technical parameters in the production process.
5. The raw materials are strip coil, welding wire and flux. Before input, it must undergo strict physical and chemical tests.
6. Strip steel head and tail butt joint, using single wire or double wire submerged arc welding, after coiling into steel pipe, automatic submerged arc welding machine repair welding.
7. Before forming, the strip is subjected to leveling, trimming, planing, surface cleaning and pre-bending.
8. The electric contact pressure gauge is used to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth conveyance of the strip.
9.Using external control or internal control roll forming.
10. Weld gap control device is used to ensure that the weld gap meets the welding requirements, and the pipe diameter, misalignment and weld gap are strictly controlled.
For liquid transportation: water supply and drainage.
For gas transportation: coal gas, steam, liquefied petroleum gas.
For structural use: for piling pipes and bridges; for docks, roads, and building structures.
Main technical characteristics of spiral steel pipe:
1. During the forming process, the steel plate deforms uniformly, the residual stress is small, and the surface is not scratched. The processed spiral steel pipe has more flexibility in the range of diameter and wall thickness. Especially in the production of small and medium-diameter thick-walled pipes, it has advantages that are unmatched by other processes, and can meet the user's more requirements on spiral steel pipe specifications .
2. Adopting advanced double-sided submerged arc welding technology, welding can be achieved in a good position, which is not prone to defects such as misalignment, welding deviation and under-welding, and it is easy to control welding quality.
3, 100% quality inspection of steel pipes, so that the entire process of steel pipe production under effective detection and monitoring, effectively guarantee product quality.
4. All the equipment of the whole production line has the function of networking with computer data acquisition system, real-time data transmission, and the central control room controls the technical parameters in the production process.
5. The raw materials are strip coil, welding wire and flux. Before input, it must undergo strict physical and chemical tests.
6. Strip steel head and tail butt joint, using single wire or double wire submerged arc welding, after coiling into steel pipe, automatic submerged arc welding machine repair welding.
7. Before forming, the strip is subjected to leveling, trimming, planing, surface cleaning and pre-bending.
8. The electric contact pressure gauge is used to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth conveyance of the strip.
9.Using external control or internal control roll forming.
10. Weld gap control device is used to ensure that the weld gap meets the welding requirements, and the pipe diameter, misalignment and weld gap are strictly controlled.
2020年4月19日星期日
Causes of oil and gas pipeline leakage
There are many reasons for pipeline leakage, which can be divided into three categories: corrosion perforation, fatigue cracking and external damage.
Although corrosion control measures can significantly reduce corrosion, it does not prevent corrosion. When the cathodic protection is insufficient, the pipeline corrosion process will be slow but will not stop due to cathodic protection; when the cathodic protection is shielded, the pipeline corrosion will not be inhibited at all. Insufficient cathodic protection means that the protection current provided by the cathodic protection system cannot meet the pipeline protection requirements; cathodic protection shielding means that the cathodic protection current is blocked in the flow and cannot reach the predetermined position. When a large area of damage, continuous leakage points or overall insulation performance decline on the coating, it is easy to cause insufficient cathodic protection.
If the oil and gas pipeline is operated under high pressure for a long time, the mechanical properties of the pipeline metal will gradually decay, and the micro-cracks existing in the pipeline weld itself and due to stress corrosion will expand. When the cracks develop to a certain extent, they will cause sudden pipeline rupture accident, leading to leakage. For gas pipelines, pipeline rupture may have catastrophic consequences.
External damage mainly includes natural disasters and human disasters. Floods, landslides, mudslides, and earthquakes can all damage pipelines; human disasters mainly refer to third-party damage, including unintentional damage caused by various construction projects such as road construction and excavation and deliberate damage caused by perpetrators such as drilling holes, stealing oil and gas.
http://www.xysteelpipe.com/info/Causes-of-oil-and-gas-pipeline-leakage-1654-1.htm
Although corrosion control measures can significantly reduce corrosion, it does not prevent corrosion. When the cathodic protection is insufficient, the pipeline corrosion process will be slow but will not stop due to cathodic protection; when the cathodic protection is shielded, the pipeline corrosion will not be inhibited at all. Insufficient cathodic protection means that the protection current provided by the cathodic protection system cannot meet the pipeline protection requirements; cathodic protection shielding means that the cathodic protection current is blocked in the flow and cannot reach the predetermined position. When a large area of damage, continuous leakage points or overall insulation performance decline on the coating, it is easy to cause insufficient cathodic protection.
If the oil and gas pipeline is operated under high pressure for a long time, the mechanical properties of the pipeline metal will gradually decay, and the micro-cracks existing in the pipeline weld itself and due to stress corrosion will expand. When the cracks develop to a certain extent, they will cause sudden pipeline rupture accident, leading to leakage. For gas pipelines, pipeline rupture may have catastrophic consequences.
External damage mainly includes natural disasters and human disasters. Floods, landslides, mudslides, and earthquakes can all damage pipelines; human disasters mainly refer to third-party damage, including unintentional damage caused by various construction projects such as road construction and excavation and deliberate damage caused by perpetrators such as drilling holes, stealing oil and gas.
http://www.xysteelpipe.com/info/Causes-of-oil-and-gas-pipeline-leakage-1654-1.htm
2020年4月16日星期四
ERW, SSAW, LSAW welded steel tube
ERW steel pipe: high-frequency straight seam resistance welded pipe, using hot-rolled wide coil as the material, through pre-bending, continuous forming, welding, heat treatment, sizing, straightening, blocking and other processes, it has a shorter weld seam than the spiral, standard High precision, uniform wall thickness, good surface quality, and high-end benefits under pressure, but the defect is that only small and medium-diameter thin-walled pipes can be produced, and the welds are prone to gray spots, unfused, and groove-shaped corrosion defects. At present, the widely used fields are city gas, crude oil products and oil transportation, etc.
SSAW steel pipe: spiral submerged arc welded pipe, which has a forming angle (adjustable) with the center line of the forming pipe when the pipe is rolled, and is welded while forming, and its welding seam is formed into a spiral line, and the same standard can produce a variety of diameters Standard steel pipe, the material is used to planning larger, the weld can avoid the main stress, the stress is better, the defect is a few standards are poor, the length of the weld is longer than that of the straight pipe, the crack is easy to crack, the slag is included, the welding deviation, etc. Welding defects, welding stress is tensile stress. The general design rules and regulations of long-distance spiral submerged arc for oil and gas pipelines can only be used in category 3 and category 4 areas.
LSAW steel pipe: Straight seam submerged arc welded pipe, which is made of a single medium-thick plate by pressing (rolling) the steel plate in a mold or forming machine, using double-sided submerged arc welding and expanding the diameter to produce. Its product standard planning is wide, and the resistance, plasticity, uniformity and fineness of the weld are good. It has the advantages of large pipe diameter, pipe wall thickness, high pressure resistance, low temperature resistance and corrosion resistance. When creating high-strength, high-endurance, high-quality long-distance oil and gas pipelines, most of the steel pipes required are large-diameter thick-walled straight-seam submerged arcs. According to API standard rules, in large oil and gas transportation pipelines, when passing through Class 1 and Class 2 areas such as the seabed in high cold areas and densely populated urban areas, the straight-seam submerged arc is the only designated pipe type.
SSAW steel pipe: spiral submerged arc welded pipe, which has a forming angle (adjustable) with the center line of the forming pipe when the pipe is rolled, and is welded while forming, and its welding seam is formed into a spiral line, and the same standard can produce a variety of diameters Standard steel pipe, the material is used to planning larger, the weld can avoid the main stress, the stress is better, the defect is a few standards are poor, the length of the weld is longer than that of the straight pipe, the crack is easy to crack, the slag is included, the welding deviation, etc. Welding defects, welding stress is tensile stress. The general design rules and regulations of long-distance spiral submerged arc for oil and gas pipelines can only be used in category 3 and category 4 areas.
LSAW steel pipe: Straight seam submerged arc welded pipe, which is made of a single medium-thick plate by pressing (rolling) the steel plate in a mold or forming machine, using double-sided submerged arc welding and expanding the diameter to produce. Its product standard planning is wide, and the resistance, plasticity, uniformity and fineness of the weld are good. It has the advantages of large pipe diameter, pipe wall thickness, high pressure resistance, low temperature resistance and corrosion resistance. When creating high-strength, high-endurance, high-quality long-distance oil and gas pipelines, most of the steel pipes required are large-diameter thick-walled straight-seam submerged arcs. According to API standard rules, in large oil and gas transportation pipelines, when passing through Class 1 and Class 2 areas such as the seabed in high cold areas and densely populated urban areas, the straight-seam submerged arc is the only designated pipe type.
Disadvantages of Hot Rolled 20 # Straight Seam Steel Pipe
Disadvantages of hot rolled 20 # straight seam steel pipe:
1. Residual stress caused by uneven cooling. Residual stress is the stress of internal self-phase balance without external force. Hot-rolled steel sections of various cross sections have this type of residual stress. The larger the section size of general steel section, the greater the residual stress. Although the residual stress is self-balanced, it still has a certain influence on the performance of the steel member under the action of external forces. Such as deformation, stability, fatigue resistance, etc. may have adverse effects.
2. After welding, the non-metallic inclusions in the straight seam steel pipe are pressed into thin slices, and the delamination phenomenon occurs. The delamination greatly deteriorates the performance of the 20 # straight seam steel tube in the thickness direction, and there may be interlayer tearing when the weld shrinks. The local strain induced by shrinkage of the weld often reaches several times the yield point strain, which is much larger than the strain caused by the load.
Submerged arc welding straight seam steel pipe advantages: it can destroy the casting structure of the steel ingot, refine the grain of the steel, and eliminate the defects of the microstructure, so that the steel structure is compact and the mechanical properties are improved. This improvement is mainly reflected in the rolling direction, so that the 20 # straight seam steel tube is no longer an isotropic body to a certain extent; bubbles, cracks and looseness formed during casting can also be affected by high temperature and pressure Welding.
1. Residual stress caused by uneven cooling. Residual stress is the stress of internal self-phase balance without external force. Hot-rolled steel sections of various cross sections have this type of residual stress. The larger the section size of general steel section, the greater the residual stress. Although the residual stress is self-balanced, it still has a certain influence on the performance of the steel member under the action of external forces. Such as deformation, stability, fatigue resistance, etc. may have adverse effects.
2. After welding, the non-metallic inclusions in the straight seam steel pipe are pressed into thin slices, and the delamination phenomenon occurs. The delamination greatly deteriorates the performance of the 20 # straight seam steel tube in the thickness direction, and there may be interlayer tearing when the weld shrinks. The local strain induced by shrinkage of the weld often reaches several times the yield point strain, which is much larger than the strain caused by the load.
Submerged arc welding straight seam steel pipe advantages: it can destroy the casting structure of the steel ingot, refine the grain of the steel, and eliminate the defects of the microstructure, so that the steel structure is compact and the mechanical properties are improved. This improvement is mainly reflected in the rolling direction, so that the 20 # straight seam steel tube is no longer an isotropic body to a certain extent; bubbles, cracks and looseness formed during casting can also be affected by high temperature and pressure Welding.
The role of oil casing and oil drill pipe
The casing pipe is used to strengthen the well wall, and the inner and outer diameters are much larger than the drill rod; the drill rod is used to connect the drill collar and the drill bit, and the length is sufficient to support the drill bit in the downhole operation. Regardless of function or size, they are all different.
The essence of the casing pipe is:
1. During the drilling process, as the depth of the well increases, the required mud density will increase, and the upper bottom layer may be leaked. The role of the casing is to prevent the upper layer from being leaked when drilling the lower layer.
2. The last oil pipe and tail pipe is the oil passage. The purpose is to stabilize the formation and prevent collapse. If the formation is hard, the well can be completed with open holes.
Open-hole completion can only be applied to a single oil or gas layer with hard and dense rock formations, no water-containing interlayers, and no easy-to-collapse interlayers or some oil and gas layers with the same properties and similar pressures.
http://www.xysteelpipe.com/info/The-role-of-oil-casing-and-oil-drill-pipe-1653-1.htm
The essence of the casing pipe is:
1. During the drilling process, as the depth of the well increases, the required mud density will increase, and the upper bottom layer may be leaked. The role of the casing is to prevent the upper layer from being leaked when drilling the lower layer.
2. The last oil pipe and tail pipe is the oil passage. The purpose is to stabilize the formation and prevent collapse. If the formation is hard, the well can be completed with open holes.
Open-hole completion can only be applied to a single oil or gas layer with hard and dense rock formations, no water-containing interlayers, and no easy-to-collapse interlayers or some oil and gas layers with the same properties and similar pressures.
http://www.xysteelpipe.com/info/The-role-of-oil-casing-and-oil-drill-pipe-1653-1.htm
2020年3月30日星期一
Spiral welded steel tube
Helical welded pipes is the low-carbon structural steel or low alloy steel
strip by the helix angle (called molding angle) rolled into a tube, and then the
tube made of seam welded together, it can be used a narrow bandsteel production
of large-diameter steel pipe. Helical welded pipes for oil pipeline and gas
pipeline specifications diameter * wall thickness. Helical welded pipes side
welding and double-sided welding, the pipe should ensure that hydrostatic test,
weld tensile strength and cold performance to meet the requirements.
The process of helical welded pipes is as follows:
Open book - on volume - leveling - butt welding - Milling - molding - welding - Weld - cut pipe - break - the follow-up welding - hydrostatic test
Uses of helical welded pipes:
Helical welded pipes are mainly used in water engineering, petrochemical industry, chemical industry, power industry, agricultural irrigation, urban construction in the country. For the transport of liquids: water supply, drainage. For gas transportation: gas, steam, liquefied petroleum gas. For structural purposes: as piling pipe for bridges; docks, roads, building structure pipe.
The process of helical welded pipes is as follows:
Open book - on volume - leveling - butt welding - Milling - molding - welding - Weld - cut pipe - break - the follow-up welding - hydrostatic test
Uses of helical welded pipes:
Helical welded pipes are mainly used in water engineering, petrochemical industry, chemical industry, power industry, agricultural irrigation, urban construction in the country. For the transport of liquids: water supply, drainage. For gas transportation: gas, steam, liquefied petroleum gas. For structural purposes: as piling pipe for bridges; docks, roads, building structure pipe.
Groove of steel pipe
Definition: According to the design or process needs, the weldments to be
welded processed and assembled into a certain groove geometry, called
groove.
Purpose: the open groove is to get all of the weldment thickness penetration welds. Groove is primarily for welding parts, to ensure the welding degrees, with machining methods machined-surface under ordinary circumstances, can also be gas cutting when requirement is low (if it is A class of welds, ultrasonic testing required, you can only use the machine processing methods), but need to remove the oxide slag.
Common groove forms are: butt groove and angular contact groove (on the project in order to distinguish the butt corner joints and general butt welds, now divided into docking, pick bevel, fillet three categories).
Butt groove mainly: I type, V-type, X-type, U-type, Y-type, UV type, VV type, etc.
Fillet groove are: T-type, lap, J type, etc.
Welding groove criteria:
CB 1220-1993 921A, 922A steel welding groove basic types and sizes
CB / T 3190-1997 hull structure welding groove types and sizes
GB 985-88 welding, SMAW basic form and GMAW weld groove basic types and sizes
GB 986-88 submerged arc weld groove basic types and sizes
Welding groove index
1, Appearance: no cracks, delamination, inclusions and other defects
2, Size: as required examination direction drawings and WPS, angle, blunt edge, set gap
3, low-alloy steel material Rm≥540Mpa and Cr-Mo steel bevel should be in accordance with JB / T4730.4-2005 to do MT detection.
4, non-ferrous and stainless steel bevel with special requirements on the drawing should be carried out to do PT detection.
5, the slope of the base metal surface on both sides of the mouth, at least within the range of 20mm should remove the descaling, oil, slag and other harmful contaminants
Purpose: the open groove is to get all of the weldment thickness penetration welds. Groove is primarily for welding parts, to ensure the welding degrees, with machining methods machined-surface under ordinary circumstances, can also be gas cutting when requirement is low (if it is A class of welds, ultrasonic testing required, you can only use the machine processing methods), but need to remove the oxide slag.
Common groove forms are: butt groove and angular contact groove (on the project in order to distinguish the butt corner joints and general butt welds, now divided into docking, pick bevel, fillet three categories).
Butt groove mainly: I type, V-type, X-type, U-type, Y-type, UV type, VV type, etc.
Fillet groove are: T-type, lap, J type, etc.
Welding groove criteria:
CB 1220-1993 921A, 922A steel welding groove basic types and sizes
CB / T 3190-1997 hull structure welding groove types and sizes
GB 985-88 welding, SMAW basic form and GMAW weld groove basic types and sizes
GB 986-88 submerged arc weld groove basic types and sizes
Welding groove index
1, Appearance: no cracks, delamination, inclusions and other defects
2, Size: as required examination direction drawings and WPS, angle, blunt edge, set gap
3, low-alloy steel material Rm≥540Mpa and Cr-Mo steel bevel should be in accordance with JB / T4730.4-2005 to do MT detection.
4, non-ferrous and stainless steel bevel with special requirements on the drawing should be carried out to do PT detection.
5, the slope of the base metal surface on both sides of the mouth, at least within the range of 20mm should remove the descaling, oil, slag and other harmful contaminants
Inspection method for oil bushing manufacturer
What are the detection methods of oil casing pipe ? Let's take a brief look:
1. Ultrasonic testing
When ultrasonic waves are spread in the tested raw materials, the acoustic characteristics of the raw materials and the changes in the internal organization have a positive impact on the spread of the ultrasonic waves. After detecting the affected levels and conditions of the ultrasonic waves, the changes in the function and structure of the raw materials are understood .
2. Radiographic inspection
Radiographic inspection uses the difference in the amount of radiation transmitted between the normal part and the defective part to form the resolution of the blackness on the negative.
3. Penetrant test
Penetrant test is to use the capillary action of liquid to permeate the penetrant into the opening on the surface of the solid raw material, and then draw the penetrant penetrant to the surface through the developer to show the existence of the defect. Penetration testing is suitable for a variety of metal and ceramic workpieces, and the time from penetration manipulation to the appearance of defects is relatively short, usually about half an hour. It may be useful to detect surface fatigue, stress corrosion and welding cracks, and to directly measure the size of cracks.
4. Magnetic particle detection
Magnetic particle detection is to use magnetic flux leakage to absorb magnetic particles and form magnetic marks to provide defect manifestation. It can detect surface and subsurface defects. The nature of defects is easy to distinguish. Paint and electroplated surfaces do not affect the detection vividness.
5. Eddy current detection
If the eddy current detection mainly uses the eddy current induced in the workpiece by the ferromagnetic coil to analyze the internal quality of the workpiece, it can detect the shortcomings of the surface and near surface of various conductive raw materials, the usual parameter control is troublesome, and the detection results are difficult to explain. Moreover, it is required that the detection object must be a conductive crack, and the length of the fault can be measured euphemistically.
6. Magnetic flux leakage detection
Magnetic flux leakage detection of petroleum casing is based on the characteristics of high permeability of ferromagnetic materials. Basically, the quality of in-service petroleum casing is tested by measuring the permeability change caused by defects in ferromagnetic materials .
7. Magnetic impression detection
Magnetic impression detection is derived from the relationship between the physical nature of the magnetic phenomenon of metals and the dislocation process. It has many advantages such as high utilization, low cost, and no grinding. It has an important and ordinary application prospect in the industry.
In order to improve the service life of oil well pipes and reduce costs, oilfields require oil well pipes to be reused multiple times, which puts forward requirements for excellent anti-stick performance of oil pipes. If the oil pipe is stuck, the integrity of the thread connection will be damaged. Continued use may cause leakage at the thread connection and decrease the connection strength. Serious problems such as falling off the well may cause huge economic losses to the oilfield.
The API specification requires that the tubing can be shackled 6 times without sticking when in use. Although the well conditions of each oil field are different, the conditions of the buckle (the method of buckle, the torque of the buckle and the speed of the buckle) are not the same when the tubing goes down. The requirements for the number of trips on the tubing are different. It is required that the number of trips of the oil pipe can reach more than 10 times, and some oilfields require more than 30 times.
http://www.xysteelpipe.com/info/Inspection-method-for-oil-bushing-manufacturer-1641-1.htm
1. Ultrasonic testing
When ultrasonic waves are spread in the tested raw materials, the acoustic characteristics of the raw materials and the changes in the internal organization have a positive impact on the spread of the ultrasonic waves. After detecting the affected levels and conditions of the ultrasonic waves, the changes in the function and structure of the raw materials are understood .
2. Radiographic inspection
Radiographic inspection uses the difference in the amount of radiation transmitted between the normal part and the defective part to form the resolution of the blackness on the negative.
3. Penetrant test
Penetrant test is to use the capillary action of liquid to permeate the penetrant into the opening on the surface of the solid raw material, and then draw the penetrant penetrant to the surface through the developer to show the existence of the defect. Penetration testing is suitable for a variety of metal and ceramic workpieces, and the time from penetration manipulation to the appearance of defects is relatively short, usually about half an hour. It may be useful to detect surface fatigue, stress corrosion and welding cracks, and to directly measure the size of cracks.
4. Magnetic particle detection
Magnetic particle detection is to use magnetic flux leakage to absorb magnetic particles and form magnetic marks to provide defect manifestation. It can detect surface and subsurface defects. The nature of defects is easy to distinguish. Paint and electroplated surfaces do not affect the detection vividness.
5. Eddy current detection
If the eddy current detection mainly uses the eddy current induced in the workpiece by the ferromagnetic coil to analyze the internal quality of the workpiece, it can detect the shortcomings of the surface and near surface of various conductive raw materials, the usual parameter control is troublesome, and the detection results are difficult to explain. Moreover, it is required that the detection object must be a conductive crack, and the length of the fault can be measured euphemistically.
6. Magnetic flux leakage detection
Magnetic flux leakage detection of petroleum casing is based on the characteristics of high permeability of ferromagnetic materials. Basically, the quality of in-service petroleum casing is tested by measuring the permeability change caused by defects in ferromagnetic materials .
7. Magnetic impression detection
Magnetic impression detection is derived from the relationship between the physical nature of the magnetic phenomenon of metals and the dislocation process. It has many advantages such as high utilization, low cost, and no grinding. It has an important and ordinary application prospect in the industry.
In order to improve the service life of oil well pipes and reduce costs, oilfields require oil well pipes to be reused multiple times, which puts forward requirements for excellent anti-stick performance of oil pipes. If the oil pipe is stuck, the integrity of the thread connection will be damaged. Continued use may cause leakage at the thread connection and decrease the connection strength. Serious problems such as falling off the well may cause huge economic losses to the oilfield.
The API specification requires that the tubing can be shackled 6 times without sticking when in use. Although the well conditions of each oil field are different, the conditions of the buckle (the method of buckle, the torque of the buckle and the speed of the buckle) are not the same when the tubing goes down. The requirements for the number of trips on the tubing are different. It is required that the number of trips of the oil pipe can reach more than 10 times, and some oilfields require more than 30 times.
http://www.xysteelpipe.com/info/Inspection-method-for-oil-bushing-manufacturer-1641-1.htm
2020年3月29日星期日
Inspection method for oil bushing manufacturer
What are the detection methods of oil casing pipe ? Let's take a brief look:
1. Ultrasonic testing
When ultrasonic waves are spread in the tested raw materials, the acoustic characteristics of the raw materials and the changes in the internal organization have a positive impact on the spread of the ultrasonic waves. After detecting the affected levels and conditions of the ultrasonic waves, the changes in the function and structure of the raw materials are understood .
2. Radiographic inspection
Radiographic inspection uses the difference in the amount of radiation transmitted between the normal part and the defective part to form the resolution of the blackness on the negative.
3. Penetrant test
Penetrant test is to use the capillary action of liquid to permeate the penetrant into the opening on the surface of the solid raw material, and then draw the penetrant penetrant to the surface through the developer to show the existence of the defect. Penetration testing is suitable for a variety of metal and ceramic workpieces, and the time from penetration manipulation to the appearance of defects is relatively short, usually about half an hour. It may be useful to detect surface fatigue, stress corrosion and welding cracks, and to directly measure the size of cracks.
4. Magnetic particle detection
Magnetic particle detection is to use magnetic flux leakage to absorb magnetic particles and form magnetic marks to provide defect manifestation. It can detect surface and subsurface defects. The nature of defects is easy to distinguish. Paint and electroplated surfaces do not affect the detection vividness.
5. Eddy current detection
If the eddy current detection mainly uses the eddy current induced in the workpiece by the ferromagnetic coil to analyze the internal quality of the workpiece, it can detect the shortcomings of the surface and near surface of various conductive raw materials, the usual parameter control is troublesome, and the detection results are difficult to explain. Moreover, it is required that the detection object must be a conductive crack, and the length of the fault can be measured euphemistically.
6. Magnetic flux leakage detection
Magnetic flux leakage detection of petroleum casing is based on the characteristics of high permeability of ferromagnetic materials. Basically, the quality of in-service petroleum casing is tested by measuring the permeability change caused by defects in ferromagnetic materials .
7. Magnetic impression detection
Magnetic impression detection is derived from the relationship between the physical nature of the magnetic phenomenon of metals and the dislocation process. It has many advantages such as high utilization, low cost, and no grinding. It has an important and ordinary application prospect in the industry.
In order to improve the service life of oil well pipes and reduce costs, oilfields require oil well pipes to be reused multiple times, which puts forward requirements for excellent anti-stick performance of oil pipes. If the oil pipe is stuck, the integrity of the thread connection will be damaged. Continued use may cause leakage at the thread connection and decrease the connection strength. Serious problems such as falling off the well may cause huge economic losses to the oilfield.
The API specification requires that the tubing can be shackled 6 times without sticking when in use. Although the well conditions of each oil field are different, the conditions of the buckle (the method of buckle, the torque of the buckle and the speed of the buckle) are not the same when the tubing goes down. The requirements for the number of trips on the tubing are different. It is required that the number of trips of the oil pipe can reach more than 10 times, and some oilfields require more than 30 times.
1. Ultrasonic testing
When ultrasonic waves are spread in the tested raw materials, the acoustic characteristics of the raw materials and the changes in the internal organization have a positive impact on the spread of the ultrasonic waves. After detecting the affected levels and conditions of the ultrasonic waves, the changes in the function and structure of the raw materials are understood .
2. Radiographic inspection
Radiographic inspection uses the difference in the amount of radiation transmitted between the normal part and the defective part to form the resolution of the blackness on the negative.
3. Penetrant test
Penetrant test is to use the capillary action of liquid to permeate the penetrant into the opening on the surface of the solid raw material, and then draw the penetrant penetrant to the surface through the developer to show the existence of the defect. Penetration testing is suitable for a variety of metal and ceramic workpieces, and the time from penetration manipulation to the appearance of defects is relatively short, usually about half an hour. It may be useful to detect surface fatigue, stress corrosion and welding cracks, and to directly measure the size of cracks.
4. Magnetic particle detection
Magnetic particle detection is to use magnetic flux leakage to absorb magnetic particles and form magnetic marks to provide defect manifestation. It can detect surface and subsurface defects. The nature of defects is easy to distinguish. Paint and electroplated surfaces do not affect the detection vividness.
5. Eddy current detection
If the eddy current detection mainly uses the eddy current induced in the workpiece by the ferromagnetic coil to analyze the internal quality of the workpiece, it can detect the shortcomings of the surface and near surface of various conductive raw materials, the usual parameter control is troublesome, and the detection results are difficult to explain. Moreover, it is required that the detection object must be a conductive crack, and the length of the fault can be measured euphemistically.
6. Magnetic flux leakage detection
Magnetic flux leakage detection of petroleum casing is based on the characteristics of high permeability of ferromagnetic materials. Basically, the quality of in-service petroleum casing is tested by measuring the permeability change caused by defects in ferromagnetic materials .
7. Magnetic impression detection
Magnetic impression detection is derived from the relationship between the physical nature of the magnetic phenomenon of metals and the dislocation process. It has many advantages such as high utilization, low cost, and no grinding. It has an important and ordinary application prospect in the industry.
In order to improve the service life of oil well pipes and reduce costs, oilfields require oil well pipes to be reused multiple times, which puts forward requirements for excellent anti-stick performance of oil pipes. If the oil pipe is stuck, the integrity of the thread connection will be damaged. Continued use may cause leakage at the thread connection and decrease the connection strength. Serious problems such as falling off the well may cause huge economic losses to the oilfield.
The API specification requires that the tubing can be shackled 6 times without sticking when in use. Although the well conditions of each oil field are different, the conditions of the buckle (the method of buckle, the torque of the buckle and the speed of the buckle) are not the same when the tubing goes down. The requirements for the number of trips on the tubing are different. It is required that the number of trips of the oil pipe can reach more than 10 times, and some oilfields require more than 30 times.
Surface treatment method and function of stainless steel tube
The surface of the stainless steel pipe will change differently in different environments. Knowing the influence of the use environment on the stainless steel pipe can choose the right model, otherwise the stainless steel pipe will rust and corrode.
Pretreatment is an important treatment step before the surface of stainless steel pipe enters the surface treatment (including pickling, chemical polishing and electrochemical polishing, electroplating, passivation, blackening, coloring, chemical processing, etc.). During the forming process of stainless steel pipes, the surface may be stained with oil, burrs, and rough surfaces and oxides. Therefore, before surface treatment, the oil, burrs, uneven surfaces and oxides must be removed to enable subsequent processing. Get satisfactory results.
The dirt on the surface of the stainless steel pipe to be removed in the pretreatment, it can be divided into two categories: organic and inorganic. Organic pollutants: including mineral oils (such as diesel, motor oil, petroleum jelly, paraffin, etc.) and animal and vegetable oils (such as soybean oil, tea oil, rapeseed oil, lard, tallow, etc.). These oil pollution mainly come from the processing of stainless steel pipes. Used lubricants, cutting oils, quenching oils, polishing and polishing pastes, and fingerprints. Inorganic dirt: Including dirt, dust particles, and oxides generated during heat treatment.
The procedure of stainless steel pipe pretreatment is as follows:
(1) Mechanical leveling of the surface: Eliminate the rough state of the stainless steel surface, and achieve a certain surface finish after mechanical grinding and polishing.
(2) Degreasing: degreasing on the surface,
(3) Pickling: remove the oxide on the surface.
(4) Weak corrosion: Activate the surface to be treated, remove the surface passivation film, and expose the metal crystal structure.
The surface pretreatment method of stainless steel pipe is as follows:
(1) Mechanical method: Use a polisher, polisher or other machinery to remove the rough surface, and then polish and polish it.
(2) Chemical method: degreasing with alkali solution, acid washing with acid solution and organic solvent to dissolve grease and decontamination.
(3) Electrochemical method: the application of electrochemical degreasing and electrochemical etching.
(4) Rolling light, centrifugal light, centrifugal plate light decoration and rotating light decoration, suitable for small parts.
(5) Sand blasting: suitable for large area treatment, and has the functions of decontamination and oxide scale removal.
Therefore, according to the different surface conditions, the quality requirements for the subsequent treatment of stainless steel pipes, using appropriate pretreatment methods.
Pretreatment is an important treatment step before the surface of stainless steel pipe enters the surface treatment (including pickling, chemical polishing and electrochemical polishing, electroplating, passivation, blackening, coloring, chemical processing, etc.). During the forming process of stainless steel pipes, the surface may be stained with oil, burrs, and rough surfaces and oxides. Therefore, before surface treatment, the oil, burrs, uneven surfaces and oxides must be removed to enable subsequent processing. Get satisfactory results.
The dirt on the surface of the stainless steel pipe to be removed in the pretreatment, it can be divided into two categories: organic and inorganic. Organic pollutants: including mineral oils (such as diesel, motor oil, petroleum jelly, paraffin, etc.) and animal and vegetable oils (such as soybean oil, tea oil, rapeseed oil, lard, tallow, etc.). These oil pollution mainly come from the processing of stainless steel pipes. Used lubricants, cutting oils, quenching oils, polishing and polishing pastes, and fingerprints. Inorganic dirt: Including dirt, dust particles, and oxides generated during heat treatment.
The procedure of stainless steel pipe pretreatment is as follows:
(1) Mechanical leveling of the surface: Eliminate the rough state of the stainless steel surface, and achieve a certain surface finish after mechanical grinding and polishing.
(2) Degreasing: degreasing on the surface,
(3) Pickling: remove the oxide on the surface.
(4) Weak corrosion: Activate the surface to be treated, remove the surface passivation film, and expose the metal crystal structure.
The surface pretreatment method of stainless steel pipe is as follows:
(1) Mechanical method: Use a polisher, polisher or other machinery to remove the rough surface, and then polish and polish it.
(2) Chemical method: degreasing with alkali solution, acid washing with acid solution and organic solvent to dissolve grease and decontamination.
(3) Electrochemical method: the application of electrochemical degreasing and electrochemical etching.
(4) Rolling light, centrifugal light, centrifugal plate light decoration and rotating light decoration, suitable for small parts.
(5) Sand blasting: suitable for large area treatment, and has the functions of decontamination and oxide scale removal.
Therefore, according to the different surface conditions, the quality requirements for the subsequent treatment of stainless steel pipes, using appropriate pretreatment methods.
Most anticorrosive steel tubes are spiral steel tubes
In recent years, anticorrosive steel pipes have begun to be widely used in the construction of water and natural gas pipelines. Anti-corrosion steel pipes are usually selected from spiral steel pipes. The diameter of spiral steel pipes is usually relatively large, which is in line with the current requirements of water pipelines, natural gas pipelines and thermal pipelines.
1. Compared with the profile steel in the form of ordinary open section, the round pipe and square (rectangular) section have the characteristics of flat surface, no dead angle and small external surface area. Spiral steel pipe is conducive to saving anti-corrosion and fire-resistant coatings, and easy to remove dust.
a. During the forming process, the steel plate is uniformly deformed, the residual stress is small, and the surface is not scratched. The processed spiral steel pipe has greater flexibility in the size and size range of diameter and wall thickness, especially in the production of high-steel-grade thick-walled pipes, especially small and medium-caliber thick-walled pipes. More requirements for spiral steel pipe specifications.
b. Adopting advanced double-sided submerged arc welding technology, welding can be achieved in an excellent position, which is not prone to defects such as misalignment, welding deviation, and incomplete penetration, and it is easy to control the quality of welding.
c. 100% quality inspection of steel pipes makes the whole process of steel pipe production under effective inspection and monitoring, which effectively guarantees product quality.
d. All the equipment of the entire production line has the function of networking with the computer data acquisition system, real-time data transmission, and the central control room controls the technical parameters in the production process.
2. The wind resistance coefficient of the steel pipe section is small, and it has significant advantages when exposed to fluids (such as wind and water flow).
3. The internal space of the steel pipe structure is available. For example, filled concrete steel pipe can not only improve the bearing capacity of the component, but also extend the fire resistance limit of the component; water is injected into the tube, and the internal water circulation can be used for fire prevention.
4. Liquid can be transported in the pipe. At present, oil pipeline bridges and rainwater drainage pipes have been developed based on this feature.
5. Prestressing cables can also be placed in the tube to apply prestressing in the body.
http://www.xysteelpipe.com/info/Most-anticorrosive-steel-tubes-are-spiral-steel-tubes-1640-1.htm
1. Compared with the profile steel in the form of ordinary open section, the round pipe and square (rectangular) section have the characteristics of flat surface, no dead angle and small external surface area. Spiral steel pipe is conducive to saving anti-corrosion and fire-resistant coatings, and easy to remove dust.
a. During the forming process, the steel plate is uniformly deformed, the residual stress is small, and the surface is not scratched. The processed spiral steel pipe has greater flexibility in the size and size range of diameter and wall thickness, especially in the production of high-steel-grade thick-walled pipes, especially small and medium-caliber thick-walled pipes. More requirements for spiral steel pipe specifications.
b. Adopting advanced double-sided submerged arc welding technology, welding can be achieved in an excellent position, which is not prone to defects such as misalignment, welding deviation, and incomplete penetration, and it is easy to control the quality of welding.
c. 100% quality inspection of steel pipes makes the whole process of steel pipe production under effective inspection and monitoring, which effectively guarantees product quality.
d. All the equipment of the entire production line has the function of networking with the computer data acquisition system, real-time data transmission, and the central control room controls the technical parameters in the production process.
2. The wind resistance coefficient of the steel pipe section is small, and it has significant advantages when exposed to fluids (such as wind and water flow).
3. The internal space of the steel pipe structure is available. For example, filled concrete steel pipe can not only improve the bearing capacity of the component, but also extend the fire resistance limit of the component; water is injected into the tube, and the internal water circulation can be used for fire prevention.
4. Liquid can be transported in the pipe. At present, oil pipeline bridges and rainwater drainage pipes have been developed based on this feature.
5. Prestressing cables can also be placed in the tube to apply prestressing in the body.
http://www.xysteelpipe.com/info/Most-anticorrosive-steel-tubes-are-spiral-steel-tubes-1640-1.htm
2020年3月12日星期四
Advantages and disadvantages of cold rolled steel pipe
Hot-rolled seamless pipe is relative to cold-rolled seamless pipe. Cold-rolled seamless pipe is rolled below the recrystallization temperature, and hot-rolled seamless pipe is rolled above the recrystallization temperature.
Advantages: It can destroy the casting structure of the steel ingot, refine the grains of the steel, and eliminate the defects of the microstructure, thereby making the steel structure dense and improving the mechanical properties. This improvement is mainly reflected in the rolling direction, so that the steel is no longer an isotropic body to a certain extent. Bubbles, cracks and looseness formed during casting can also be welded under high temperature and pressure.
Disadvantages:
1. After hot rolling, non-metallic inclusions (mainly sulfides and oxides, as well as silicates) inside the steel are pressed into flakes, and delamination (interlayer) occurs. Delamination greatly deteriorates the tensile properties of the steel in the thickness direction, and interlayer tearing may occur when the weld seam shrinks. The local strain induced by the shrinkage of the weld often reaches several times the yield point strain, which is much larger than the strain caused by the load.
2. Residual stress caused by uneven cooling. Residual stress is the internal self-phase equilibrium stress without external force. Hot-rolled sections of various sections have this type of residual stress. Generally, the larger the section size of the section, the larger the residual stress. Although the residual stress is self-balanced, it still has a certain effect on the performance of steel members under external forces. For example, it may have adverse effects on deformation, stability, and fatigue resistance.
3.Hot rolled steel products are difficult to control in terms of thickness and edge width. We are familiar with thermal expansion and contraction. Since hot rolling at the beginning, even if the length and thickness are up to standard,there will still be a certain negative difference after cooling. The wider the negative difference, the thicker the thickness, the more obvious the performance. Therefore, for large steel, the width, thickness, length, angle,and edge of the steel cannot be required to be too precise.
http://www.xysteelpipe.com/info/Advantages-and-disadvantages-of-cold-rolled-steel-pipe-1621-1.htm
Advantages: It can destroy the casting structure of the steel ingot, refine the grains of the steel, and eliminate the defects of the microstructure, thereby making the steel structure dense and improving the mechanical properties. This improvement is mainly reflected in the rolling direction, so that the steel is no longer an isotropic body to a certain extent. Bubbles, cracks and looseness formed during casting can also be welded under high temperature and pressure.
Disadvantages:
1. After hot rolling, non-metallic inclusions (mainly sulfides and oxides, as well as silicates) inside the steel are pressed into flakes, and delamination (interlayer) occurs. Delamination greatly deteriorates the tensile properties of the steel in the thickness direction, and interlayer tearing may occur when the weld seam shrinks. The local strain induced by the shrinkage of the weld often reaches several times the yield point strain, which is much larger than the strain caused by the load.
2. Residual stress caused by uneven cooling. Residual stress is the internal self-phase equilibrium stress without external force. Hot-rolled sections of various sections have this type of residual stress. Generally, the larger the section size of the section, the larger the residual stress. Although the residual stress is self-balanced, it still has a certain effect on the performance of steel members under external forces. For example, it may have adverse effects on deformation, stability, and fatigue resistance.
3.Hot rolled steel products are difficult to control in terms of thickness and edge width. We are familiar with thermal expansion and contraction. Since hot rolling at the beginning, even if the length and thickness are up to standard,there will still be a certain negative difference after cooling. The wider the negative difference, the thicker the thickness, the more obvious the performance. Therefore, for large steel, the width, thickness, length, angle,and edge of the steel cannot be required to be too precise.
http://www.xysteelpipe.com/info/Advantages-and-disadvantages-of-cold-rolled-steel-pipe-1621-1.htm
SHS welding technology
Self-propagating high-temperature synthesis (SHS) is a new technology for synthetic materials, and SHS welding is a new application area of the process. SHS welding is a technique that uses the heat generated by the SHS reaction and its products to weld. Combustion synthesis technology is used to place the pressed powder between the materials to be welded, and the high-temperature reaction heat synthesized by powder body combustion and the synthesized product are used as filler materials to achieve the connection between the materials to be welded under pressure. This reaction process is similar to sintering, and the purpose of pressing is to obtain a highly dense welded joint.
Generally speaking, SHS welding has three processes: ignition, pressurization, and insulation.
1. There are many ignition methods, such as arc, electric spark, flame, high current, high temperature furnace, electron beam, laser, high temperature radiation and microwave, chemical furnace, etc.
2. The pressure and time are the keys to the success of welding. If the SHS synthetic material is not pressurized, a large amount of pores will be caused due to the pores of the material and the gas generated during the reaction. Reactants are not allowed to remain in the weld and therefore must be densified. The usual method is to pressurize during the reaction.
3. High density may not be obtained by simply pressing, and insulation should be performed at the same time.
Compared with other welding methods, SHS welding has many advantages, mainly:
1. Due to the exothermic reaction, the material need only be heated to a temperature several hundred degrees Celsius below its melting point, which can save energy.
2. A reinforcing phase such as reinforcing particles, short fibers, and whiskers can be added to the solder to form a composite material.
3. Local heat release during SHS welding can reduce the heat-affected zone, avoid damage to the microstructure of the heat-sensitive material, and maintain the material performance.
4. Welding is a synthesizable gradient material, which is used as a solder to weld special-shaped materials to overcome the mismatch in chemical, mechanical and physical properties between the base materials.
5. Because the green body can be pressed into any shape, SHS welding is easy to weld into products that are difficult to manufacture.
6. SHS welding is suitable for surface treatment of materials.
http://www.xysteelpipe.com/info/SHS-welding-technology-1620-1.htm
Generally speaking, SHS welding has three processes: ignition, pressurization, and insulation.
1. There are many ignition methods, such as arc, electric spark, flame, high current, high temperature furnace, electron beam, laser, high temperature radiation and microwave, chemical furnace, etc.
2. The pressure and time are the keys to the success of welding. If the SHS synthetic material is not pressurized, a large amount of pores will be caused due to the pores of the material and the gas generated during the reaction. Reactants are not allowed to remain in the weld and therefore must be densified. The usual method is to pressurize during the reaction.
3. High density may not be obtained by simply pressing, and insulation should be performed at the same time.
Compared with other welding methods, SHS welding has many advantages, mainly:
1. Due to the exothermic reaction, the material need only be heated to a temperature several hundred degrees Celsius below its melting point, which can save energy.
2. A reinforcing phase such as reinforcing particles, short fibers, and whiskers can be added to the solder to form a composite material.
3. Local heat release during SHS welding can reduce the heat-affected zone, avoid damage to the microstructure of the heat-sensitive material, and maintain the material performance.
4. Welding is a synthesizable gradient material, which is used as a solder to weld special-shaped materials to overcome the mismatch in chemical, mechanical and physical properties between the base materials.
5. Because the green body can be pressed into any shape, SHS welding is easy to weld into products that are difficult to manufacture.
6. SHS welding is suitable for surface treatment of materials.
http://www.xysteelpipe.com/info/SHS-welding-technology-1620-1.htm
2020年3月11日星期三
Isothermal annealing process of steel tube heat treatment
It takes a long time to complete annealing, especially for alloy steels that are relatively cold under austenite. If the austenitized steel is cooled to a temperature slightly lower than the temperature of Ar1, the temperature is changed from A to P and then air-cooled to room temperature, which can greatly shorten the annealing time. This annealing method is called isothermal annealing.
Process: The steel is heated to a temperature higher than Ac3 (or Ac1), and after being held for a proper time, it is cooled to a certain temperature in the pearlite region quickly, and maintained isothermally, so that the austenite is transformed into pearlite, and then air-cooled to room temperature Heat treatment process.
Purpose: As with full annealing, the transition is easier to control.
Suitable for A more stable steel: high carbon steel (wc> 0.6%), alloy tool steel, high alloy steel (total amount of alloy elements> 10%). Isothermal annealing is also beneficial to obtain uniform microstructure and properties. However, it is not suitable for large-section steel parts and large batches of charge, because isothermal annealing is not easy to make the workpiece or batch workpieces reach isothermal temperature.
Process: The steel is heated to 20 ~ 30 ° C above Ac3, and heated for a period of time (using a furnace) to slowly cool down to obtain a heat treatment process (complete austenitization) close to the equilibrium structure.
Full annealing is mainly used for hypoeutectoid steel (wc = 0.3 ~ 0.6%), usually used for medium carbon steel and medium and low carbon alloy steel castings, forgings and hot-rolled profiles, and sometimes its welded parts. Low carbon steel has a lower hardness after being fully annealed, which is not conducive to cutting. When the supereutectoid steel is heated above Accm and slowly cooled and annealed, Fe3CII will precipitate in a network shape along the grain boundaries, thereby making the steel strong, hard, and malleable. And the toughness is significantly reduced, leaving a hidden danger to the final heat treatment.
China Steel Pipe Information Port Investigation Team was informed: Purpose: To refine grains, make the structure uniform, eliminate internal stress, reduce hardness and improve the machinability of steel. The microstructure of the fully annealed hypoeutectoid steel is F + P.
In actual production, in order to improve productivity, it is air-cooled to cool the annealing to about 500 ° C.
http://www.xysteelpipe.com/info/Isothermal-annealing-process-of-steel-tube-heat-treatment-1619-1.htm
Process: The steel is heated to a temperature higher than Ac3 (or Ac1), and after being held for a proper time, it is cooled to a certain temperature in the pearlite region quickly, and maintained isothermally, so that the austenite is transformed into pearlite, and then air-cooled to room temperature Heat treatment process.
Purpose: As with full annealing, the transition is easier to control.
Suitable for A more stable steel: high carbon steel (wc> 0.6%), alloy tool steel, high alloy steel (total amount of alloy elements> 10%). Isothermal annealing is also beneficial to obtain uniform microstructure and properties. However, it is not suitable for large-section steel parts and large batches of charge, because isothermal annealing is not easy to make the workpiece or batch workpieces reach isothermal temperature.
Process: The steel is heated to 20 ~ 30 ° C above Ac3, and heated for a period of time (using a furnace) to slowly cool down to obtain a heat treatment process (complete austenitization) close to the equilibrium structure.
Full annealing is mainly used for hypoeutectoid steel (wc = 0.3 ~ 0.6%), usually used for medium carbon steel and medium and low carbon alloy steel castings, forgings and hot-rolled profiles, and sometimes its welded parts. Low carbon steel has a lower hardness after being fully annealed, which is not conducive to cutting. When the supereutectoid steel is heated above Accm and slowly cooled and annealed, Fe3CII will precipitate in a network shape along the grain boundaries, thereby making the steel strong, hard, and malleable. And the toughness is significantly reduced, leaving a hidden danger to the final heat treatment.
China Steel Pipe Information Port Investigation Team was informed: Purpose: To refine grains, make the structure uniform, eliminate internal stress, reduce hardness and improve the machinability of steel. The microstructure of the fully annealed hypoeutectoid steel is F + P.
In actual production, in order to improve productivity, it is air-cooled to cool the annealing to about 500 ° C.
http://www.xysteelpipe.com/info/Isothermal-annealing-process-of-steel-tube-heat-treatment-1619-1.htm
Complete annealing process of steel tube
Process: Heat steel to 20 ~ 30 ℃ above Ac3, cool slowly after heating for a period of time (with furnace) to obtain a heat treatment process (complete austenitization) close to the equilibrium structure.
Full annealing is mainly used for hypoeutectoid steel (wc = 0.3 ~ 0.6%), generally medium carbon steel and low and medium carbon alloy steel castings, forgings and hot-rolled profiles, and sometimes also used for their weldments. Low carbon steel has a low hardness after full annealing, which is not conducive to cutting. When the hypereutectoid steel is heated to above Accm and slowly cooled and annealed, Fe3CⅡ will precipitate along the grain boundaries in a network shape, making the steel strong, hard, and plastic. And toughness are significantly reduced, leaving hidden dangers to the final heat treatment.
Purpose: To refine grains, uniform structure, eliminate internal stress, reduce hardness and improve the machinability of steel. The microstructure of the hypoeutectoid steel after complete annealing is F + P.
In actual production, in order to improve productivity, annealing cooling to about 500 ° C is air cooling.
http://www.xysteelpipe.com/info/Complete-annealing-process-of-steel-tube-1618-1.htm
Full annealing is mainly used for hypoeutectoid steel (wc = 0.3 ~ 0.6%), generally medium carbon steel and low and medium carbon alloy steel castings, forgings and hot-rolled profiles, and sometimes also used for their weldments. Low carbon steel has a low hardness after full annealing, which is not conducive to cutting. When the hypereutectoid steel is heated to above Accm and slowly cooled and annealed, Fe3CⅡ will precipitate along the grain boundaries in a network shape, making the steel strong, hard, and plastic. And toughness are significantly reduced, leaving hidden dangers to the final heat treatment.
Purpose: To refine grains, uniform structure, eliminate internal stress, reduce hardness and improve the machinability of steel. The microstructure of the hypoeutectoid steel after complete annealing is F + P.
In actual production, in order to improve productivity, annealing cooling to about 500 ° C is air cooling.
http://www.xysteelpipe.com/info/Complete-annealing-process-of-steel-tube-1618-1.htm
Welded steel pipe
Welded steel pipes, also known as seam steel pipes, are generally welded from steel plates or steel strips. According to the surface treatment of the pipe, it is divided into two types: galvanized and non-galvanized. The galvanized surface is white, also called white iron pipe or galvanized steel pipe; the surface without galvanized is ordinary welded steel pipe, also called black iron pipe. Galvanized welded steel pipes are often used for pipelines that require relatively clean transportation media, such as domestic water, purified air, and instrument air. Non-galvanized welded steel pipes can be used for steam, gas, compressed air, and condensed water.
According to user requirements, welded steel pipes can be divided into two types at the factory, one is pipe end with thread, and the other is pipe end without thread. The length of each welded steel pipe with thread at the pipe end is 4-9m, and the length of each welded steel pipe without thread is 4-12m.
Welded steel pipes are divided into thin-walled steel pipes, thickened steel pipes, and ordinary steel pipes according to different wall thicknesses. Ordinary steel pipe is the most used on the process pipeline, and its test pressure is 2.0MPa. The test pressure of the thick steel pipe is 3.0 MPa.
There are many connection methods for welded steel pipes, including screw connection, flange connection and welding. The flange connection is divided into threaded flange connection and welding flange connection, and the welding method is divided into gas welding and arc welding.
The specifications of commonly used welded steel pipes range from 6 to 150 mm in nominal diameter.
http://www.xysteelpipe.com/info/Welded-steel-pipe-1617-1.htm
According to user requirements, welded steel pipes can be divided into two types at the factory, one is pipe end with thread, and the other is pipe end without thread. The length of each welded steel pipe with thread at the pipe end is 4-9m, and the length of each welded steel pipe without thread is 4-12m.
Welded steel pipes are divided into thin-walled steel pipes, thickened steel pipes, and ordinary steel pipes according to different wall thicknesses. Ordinary steel pipe is the most used on the process pipeline, and its test pressure is 2.0MPa. The test pressure of the thick steel pipe is 3.0 MPa.
There are many connection methods for welded steel pipes, including screw connection, flange connection and welding. The flange connection is divided into threaded flange connection and welding flange connection, and the welding method is divided into gas welding and arc welding.
The specifications of commonly used welded steel pipes range from 6 to 150 mm in nominal diameter.
http://www.xysteelpipe.com/info/Welded-steel-pipe-1617-1.htm
2020年1月14日星期二
Hydraulic test of oil casing
Hydrostatic test of casing pipe:
①. Use high-pressure water gun to clean the inside of the tube;
②. The surface of the thread must be coated with lubricant to minimize damage during the hydrostatic test (plugging and unloading);
③. Correctly clamp the workpiece, check whether the various parts of the equipment are running normally;
④. Check whether the protective device is safe and reliable;
⑤. Water injection and suppression, the suppression time is 7 seconds;
⑥. Fill in "Hydrostatic Test Report of Threaded Sleeve" carefully according to the workpiece number.
①. Use high-pressure water gun to clean the inside of the tube;
②. The surface of the thread must be coated with lubricant to minimize damage during the hydrostatic test (plugging and unloading);
③. Correctly clamp the workpiece, check whether the various parts of the equipment are running normally;
④. Check whether the protective device is safe and reliable;
⑤. Water injection and suppression, the suppression time is 7 seconds;
⑥. Fill in "Hydrostatic Test Report of Threaded Sleeve" carefully according to the workpiece number.
2020年1月13日星期一
Inspection method of galvanized pipe
1 surface inspection
The inner and outer surfaces of galvanized steel pipes shall be inspected with the naked eye, one by one.
2 size check
The galvanized steel pipe should be tested on a black tube before galvanizing with a child equipment with sufficient accuracy.
3 thread inspection
Threaded galvanized steel pipe, according to YB 822 regulations, use a ring gauge to check the thread one by one.
4 Other inspections
(1) Galvanization guide uniformity test; test method: "copper sulfate impregnation method for homogeneity test of galvanized layer";
Sampling location and miles: Take 2 steel pipes for each batch, and take 1 longitudinal sample.
Cold bending test; Test method: GB244; Sampling location and several miles: Take 1 steel pipe for each batch, and take 1 longitudinal sample for each.
(3) Determination of weight of galvanized layer; Test method: "Measurement of weight of galvanized layer by antimony chloride method";
Sampling location and miles: Take 2 steel pipes for each batch, and take 1 longitudinal sample.
The inner and outer surfaces of galvanized steel pipes shall be inspected with the naked eye, one by one.
2 size check
The galvanized steel pipe should be tested on a black tube before galvanizing with a child equipment with sufficient accuracy.
3 thread inspection
Threaded galvanized steel pipe, according to YB 822 regulations, use a ring gauge to check the thread one by one.
4 Other inspections
(1) Galvanization guide uniformity test; test method: "copper sulfate impregnation method for homogeneity test of galvanized layer";
Sampling location and miles: Take 2 steel pipes for each batch, and take 1 longitudinal sample.
Cold bending test; Test method: GB244; Sampling location and several miles: Take 1 steel pipe for each batch, and take 1 longitudinal sample for each.
(3) Determination of weight of galvanized layer; Test method: "Measurement of weight of galvanized layer by antimony chloride method";
Sampling location and miles: Take 2 steel pipes for each batch, and take 1 longitudinal sample.
Knowledge of precision steel tubes
As a metal pipe with excellent properties, the use of steel pipes in the pipeline industry is very wide. In order to meet the requirements of different industries, the types of steel pipes are also constantly being enriched.
The quality of precision steel pipes is more critical because precision steel pipes are mainly used for the transportation of oil and natural gas. If these gases leak, the consequences are unthinkable, so the quality of steel pipes must be good.
In order to extend the life of the steel pipe, we need to add some alloy elements in it, so that we are struggling to increase its strength. In order to better meet the needs of the market, we can design the size and precision steel pipe according to customer requirements The accuracy requirements are also very high.
At present, one of the most widely used pipes in the pipeline industry is welded steel pipes.As the name implies, this type of steel pipe is a pipe made by welding.
With the continuous development and progress of modern manufacturing industry, the performance of this type of welded steel pipe is also constantly improving, so the popularity of this type of pipeline is also increasing.
The quality of precision steel pipes is more critical because precision steel pipes are mainly used for the transportation of oil and natural gas. If these gases leak, the consequences are unthinkable, so the quality of steel pipes must be good.
In order to extend the life of the steel pipe, we need to add some alloy elements in it, so that we are struggling to increase its strength. In order to better meet the needs of the market, we can design the size and precision steel pipe according to customer requirements The accuracy requirements are also very high.
At present, one of the most widely used pipes in the pipeline industry is welded steel pipes.As the name implies, this type of steel pipe is a pipe made by welding.
With the continuous development and progress of modern manufacturing industry, the performance of this type of welded steel pipe is also constantly improving, so the popularity of this type of pipeline is also increasing.
Production steps of spiral steel pipe
Last time we introduced the first 7 steps of the production of spiral steel pipes, this time we introduce the next 7 steps:
(8) The welded seams are inspected by an online continuous ultrasonic automatic flaw detector to ensure 100% non-destructive testing coverage of spiral steel pipes. If there is a defect, it will automatically alarm and spray the mark, and the production workers will adjust the process parameters at any time to eliminate the defect in time.
(9) The steel pipe is cut into individual pieces by an air plasma cutting machine.
(10) After cutting into a single steel pipe, the first three pipes of each batch of steel pipe must undergo a strict first inspection system to check the mechanical properties, chemical composition, fusion status, surface quality of the steel pipe and non-destructive inspection to ensure the pipe manufacturing process. After passing the qualification, it can be officially put into production.
(11) The parts with continuous sonic flaw detection marks on the welds are reviewed by manual ultrasound and x-rays. If there are any defects,
After repair, non-destructive inspection is performed again until it is confirmed that the defect has been eliminated.
(12) All pipes where steel butt welds and T-shaped joints intersect with spiral welds are inspected by x-ray television or film.
(13) Each steel pipe is subjected to a hydrostatic test, and the pressure is radial sealed. The test pressure and time are strictly controlled by the steel tube hydraulic pressure testing device. The test parameters are printed automatically.
(14) The pipe end is machined so that the end face verticality, bevel angle and blunt side are accurately controlled.
Generally, after these 14 steps, a spiral steel pipe has been formed, but such spiral steel pipes cannot be directly sent to the market, and the quality inspection of the spiral steel pipes and other aspects need to be performed.
(8) The welded seams are inspected by an online continuous ultrasonic automatic flaw detector to ensure 100% non-destructive testing coverage of spiral steel pipes. If there is a defect, it will automatically alarm and spray the mark, and the production workers will adjust the process parameters at any time to eliminate the defect in time.
(9) The steel pipe is cut into individual pieces by an air plasma cutting machine.
(10) After cutting into a single steel pipe, the first three pipes of each batch of steel pipe must undergo a strict first inspection system to check the mechanical properties, chemical composition, fusion status, surface quality of the steel pipe and non-destructive inspection to ensure the pipe manufacturing process. After passing the qualification, it can be officially put into production.
(11) The parts with continuous sonic flaw detection marks on the welds are reviewed by manual ultrasound and x-rays. If there are any defects,
After repair, non-destructive inspection is performed again until it is confirmed that the defect has been eliminated.
(12) All pipes where steel butt welds and T-shaped joints intersect with spiral welds are inspected by x-ray television or film.
(13) Each steel pipe is subjected to a hydrostatic test, and the pressure is radial sealed. The test pressure and time are strictly controlled by the steel tube hydraulic pressure testing device. The test parameters are printed automatically.
(14) The pipe end is machined so that the end face verticality, bevel angle and blunt side are accurately controlled.
Generally, after these 14 steps, a spiral steel pipe has been formed, but such spiral steel pipes cannot be directly sent to the market, and the quality inspection of the spiral steel pipes and other aspects need to be performed.
Comparison of ERW and LSAW Steel Pipes
"ERW steel pipe" is a high-frequency straight seam resistance welded pipe. It is used to transport vapor and liquid objects such as oil and natural gas, and can meet various requirements of high and low pressure. At present, it plays a pivotal role in the field of transportation pipes in the world.
1. Welded pipe refers to the ordinary "submerged arc welded steel pipe", which is represented by "SC" in electrical engineering. It can be used as water gas pipe or threaded pipe, which is relatively thick.
2. The line pipe is also a wire tube, which is relatively thin. It is indicated by "T" and can only be used as a pipe.
3. The ERW pipe is a "high-frequency resistance welded steel pipe", which is different from the ordinary welding pipe welding process. The welding seam is made by melting the base metal of the steel strip body, and the mechanical strength is better than that of the ordinary welded pipe.
"LSAW steel pipe"is a straight seam submerged arc welded steel pipe. Its main technical characteristics are as follows:
1. During the steel tube forming process, the steel plate is uniformly deformed, the residual stress is small, and the surface is not scratched. The processed steel pipe has greater flexibility in the diameter and wall thickness steel pipe size specifications, especially in the production of high-steel-grade thick-walled steel pipes, especially large-caliber thick-walled pipes, which have unmatched advantages in other processes, which can meet Users have more requirements in terms of steel pipe specifications;
2. Adopting the pre-weld and then internal-outer welding (fine welding) process, welding can be achieved at the optimal position, which is not prone to defects such as misalignment, welding deviation and under-penetration, and it is easy to control the welding quality;
3. The overall mechanical diameter expansion can effectively improve the dimensional accuracy of the steel pipe and improve the distribution of stress in the steel pipe, thereby avoiding damage due to stress corrosion, and at the same time, it is beneficial to the welding construction on site;
4. Carry out 9 100% quality inspections on steel pipes, so that the entire process of steel pipe production is under effective detection and monitoring, effectively ensuring product quality;
5. All the equipment of the whole production line has the function of networking with computer data acquisition system, realizing the real-time transmission of data, and the central control room controls the production.
http://www.xysteelpipe.com/info/Comparison-of-ERW-and-LSAW-Steel-Pipes-1594-1.htm
1. Welded pipe refers to the ordinary "submerged arc welded steel pipe", which is represented by "SC" in electrical engineering. It can be used as water gas pipe or threaded pipe, which is relatively thick.
2. The line pipe is also a wire tube, which is relatively thin. It is indicated by "T" and can only be used as a pipe.
3. The ERW pipe is a "high-frequency resistance welded steel pipe", which is different from the ordinary welding pipe welding process. The welding seam is made by melting the base metal of the steel strip body, and the mechanical strength is better than that of the ordinary welded pipe.
"LSAW steel pipe"is a straight seam submerged arc welded steel pipe. Its main technical characteristics are as follows:
1. During the steel tube forming process, the steel plate is uniformly deformed, the residual stress is small, and the surface is not scratched. The processed steel pipe has greater flexibility in the diameter and wall thickness steel pipe size specifications, especially in the production of high-steel-grade thick-walled steel pipes, especially large-caliber thick-walled pipes, which have unmatched advantages in other processes, which can meet Users have more requirements in terms of steel pipe specifications;
2. Adopting the pre-weld and then internal-outer welding (fine welding) process, welding can be achieved at the optimal position, which is not prone to defects such as misalignment, welding deviation and under-penetration, and it is easy to control the welding quality;
3. The overall mechanical diameter expansion can effectively improve the dimensional accuracy of the steel pipe and improve the distribution of stress in the steel pipe, thereby avoiding damage due to stress corrosion, and at the same time, it is beneficial to the welding construction on site;
4. Carry out 9 100% quality inspections on steel pipes, so that the entire process of steel pipe production is under effective detection and monitoring, effectively ensuring product quality;
5. All the equipment of the whole production line has the function of networking with computer data acquisition system, realizing the real-time transmission of data, and the central control room controls the production.
http://www.xysteelpipe.com/info/Comparison-of-ERW-and-LSAW-Steel-Pipes-1594-1.htm
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