HG/T 20537.3-1992 Technical requirements for austenitic stainless steel welded steel pipes for chemical plants
Some standard content:
Industry Standard of the People's Republic of China
Technical Requirements for Austenitic Stainless Steel Welded Steel Pipes for Chemical Industry HG 20537.3-92
Editor: Equipment Design Technology Center of the Ministry of Chemical Industry Approval Department: Ministry of Chemical Industry Date of Implementation: May 1, 1993
Editorial Center for Engineering Construction Standards of the Ministry of Chemical Industry
1993 Beijing
1 Subject Content and Scope of Application
This standard specifies the specifications, dimensions, manufacturing process, technical requirements, test methods, inspection rules, and marking, packaging and quality certificates of austenitic stainless steel welded steel pipes for chemical, petrochemical, pharmaceutical and other industries. This standard applies to austenitic stainless steel welded steel pipes for chemical industry (hereinafter referred to as welded pipes) produced by continuous automatic welding without welding wire. 33
2 Reference standards
GB222 "Sampling method for chemical analysis of steel and allowable deviation of chemical composition of finished products"
GB228 "Metal tensile test method"
GB241 "Metal pipe hydraulic test method"
GB246 "Metal pipe flattening test method"
GB2102 "General provisions for acceptance, packaging, marking and quality assurance of steel pipes" GB2975 "Steel mechanical and process test sampling regulations" GB3280 "Stainless steel cold rolled steel plate"
GB3323 "Steel fusion welded butt joint radiography and quality classification" GB4230 "Stainless steel hot rolled strip"|| tt||GB4237 "Hot-rolled Stainless Steel Plate"
GB4239 "Cold-rolled Stainless Steel and Heat-resistant Steel Strip" GB4334.5 "Stainless Steel Sulfuric Acid-Copper Sulfate Corrosion Test Method" GB7735 "Eddy Current Flaw Detection Method for Steel Pipe"
HG20537.1 "Selection Rules for Austenitic Stainless Steel Welded Steel Pipe" JB4708 "Welding Procedure Qualification for Steel Pressure Vessels" JB/T4709 "Welding Code for Steel Pressure Vessels" 34
3 Dimensions, Shape and Weight
3.0.1 For welded pipes with an outer diameter that conforms to the international general series, see Table A-1 for common specifications; for welded pipes with an outer diameter that conforms to the domestic series, see Table A-2 for common specifications. Welded pipes with specifications other than those in Table A-1 and Table A-2 may be produced by agreement between the two parties. 3.0.2 The usual length of welded pipes is 3m-9m, and welded pipes with lengths other than the above may be produced by agreement between the two parties.
The fixed length of welded pipe is generally 6m, and the allowable deviation of fixed length is +6mm. After forming, welded pipe shall not be spliced in the length direction. 3.0.3 Appearance
3.0.3.1 The two ends of a 3m long ruler are in contact with the steel pipe, and its local deflection shall not be greater than 3mm. For welded pipes with a length of less than 3m, the actual length can be converted in proportion. 3.0.3.2 The ends of welded pipes shall be free of burrs, and the two ends shall be perpendicular to the axis of the steel pipe. 3.0.4 Welded pipes shall be delivered according to actual weight or theoretical weight. Table A-1 and Table A-2 list the theoretical weights of austenitic stainless steels such as 0Cr18Ni9.00Cr19Ni10, 0Cr18Ni10Ti.1Cr18Ni9Ti. If used for OCr17Ni12Mo2 and 00Cr17Ni14Mo2, the theoretical weight listed in the table shall be increased by 0.63%. The theoretical weight calculation formula is shown in Table 3.0.4. Table 3.0.4
Chromium-nickel (titanium) austenitic stainless steel
Chromium-nickel-molybdenum austenitic stainless steel
W= 0.02491t(D--t)
W=0.02507t(D-- t)
W Theoretical weight of welded pipe, kg/m
D Outer diameter of welded pipe.mm;
t-wall thickness, mm.
Density (g/cm)
3.0.5 The allowable deviation of the outer diameter of the welded pipe, including ovality, shall be in accordance with the provisions of Table 3.0.5. 35
Nominal diameter DN, mm
>150~～300
Allowable deviation
±0.75%, minimum value ±0.3mm
3.0.6 The wall thickness allowable deviation of welded pipe (excluding weld) is ±10% of the specified wall thickness, but the minimum allowable deviation is ±0.2mm.
4 Technical requirements
4.0.1: The chemical composition (melting analysis) of the steel strip or steel plate used for welded pipe shall comply with the provisions of GB3280.GB4230, GB4237.GB4239. The welded pipe is made of hot-rolled or cold-rolled steel strip or steel plate of the commonly used steel listed in Table 4.0.1. With the agreement of both parties, it can also be made of other grades of austenitic stainless steel plates and strips. Commonly used steel grades
Cr18Ni9
OCr18Ni10Ti
00Cr19Ni10
Equivalent to AISI code
(1Cr18Ni9Ti)
0Cr17Ni12Mo2
00Cr17Ni14Mo2
Note: 1Cr18Ni9Ti is not recommended for use4.0.2 Manufacturing method
Equivalent to AISI code
4.0.2.1 The welded pipe shall be welded by automatic arc welding method without welding wire, including plasma welding and argon arc welding. Resistance explosion process can also be used, but the internal burrs must be removed. 4.0.2.2 Steel strips are allowed to be spliced, but they shall comply with the provisions of JB4708 and JB/T4709. The weld should be polished and smooth, and 100% radiographic flaw detection should be performed according to the provisions of GB3323. The sub-grade is qualified.
4.0.2.3 To remove the inner side excess height of the weld of the welded pipe, cold drawing (rolling) or other cold processing processes can be used.
4.0.3 Unless otherwise specified, the welded pipe should be subjected to solid solution treatment or stabilization treatment, and pickling and passivation treatment. If protective atmosphere heat treatment is used, pickling and passivation treatment after heat treatment can be exempted.
The recommended heat treatment system is shown in Table 4.0.3. 4.0.4 Surface quality
4.0.4.1 The inner and outer surfaces of the welded pipe shall be bright, without residual acid and oxide scale. The surface of Table 37
m shall not have defects such as cracks, inclusions, scars, delamination, weld concave, incomplete penetration, etc. Slight indentations, scratches, and pits are allowed, but their depth shall not exceed half of the negative deviation of the wall thickness. Defects exceeding the above provisions are allowed to be ground. The ground area shall have a smooth transition with the base material and the minimum thickness of the pipe wall shall be guaranteed. If welding is used, the purchaser’s consent must be obtained. The welding materials and welding process assessment of ear welding repairs shall comply with the provisions of JB4708 and JB/T4709. Heat treatment system and mechanical properties
Tensile strength Yield strength 90.2 Elongation 85 steel
OCr18Ni9
OCr18Ni10Ti
(1Cr18Ni9Ti)
00Cr19Ni10
Recommended heat treatment system
Quick cooling above 1010℃
Quick cooling above 920℃
Quick cooling above 1000℃
Quick cooling above 1010℃||t t||1010℃ or above rapid cooling
OCr17Ni12Mo2
00Cr17Ni14M02
1010℃ or above rapid coolingwwW.bzxz.Net
Not less than
Note: ①1Cr18Ni9Ti is not recommended for use. Steel grade: MPa
Not less than
②For OCr18Ni10Ti and 1Cr18Ni9Ti, the purchaser may specify stabilization heat treatment, at which time the heat treatment temperature is 850930℃ rapid cooling. 4.0.4.2 The inner weld of arc welded pipes shall be smooth and uniform, and defects such as weld nodules, weld slag, undercuts, and depressions are not allowed. The inner side height of the weld shall not exceed 15% of the wall thickness. By agreement between the two parties, welded pipes with smooth inner walls can be provided, but this should be noted when ordering. The internal burrs of the resistance welded pipe shall be completely removed without obvious traces. 4.0.4.3 The outer side of the weld shall be removed and flush with the outer surface without obvious weld traces.
4.0.5 Mechanical properties
The mechanical properties of the welded pipe shall be in accordance with the provisions of Table 4.0.3. Except for the whole pipe stretching, the sampling of the mechanical properties test may not include the weld area. 4.0.6 Flattening test
The welded pipe shall be subjected to a flattening test. During the test, the weld shall be placed at a right angle to the compression direction. Flatten the steel pipe straight until the distance between the two plates is not greater than the H value calculated by the following formula. At this time, no cracks or fissures shall appear on the inner and outer surfaces and end faces of the specimen. In:
H= 0. 09+t/D
H-distance between the two plates, mm:
D-outer diameter of the welded pipe, mm;
t-wall thickness, mm.
4.0.7 Water pressure test
Welded pipes should be subjected to water pressure test one by one. Usually the test pressure is in accordance with Table 4.0.7.1
4.0.7.1. The purchaser may also propose other water pressure test pressures. However, in general, the maximum water pressure test pressure shall not exceed the calculated value of the following formula. 2at
Wherein:
Water pressure test pressure, MPa:
---stress, take 50% of the yield strength of steel listed in Table 4.0.3, MPa; t--wall thickness, mm;
Outer diameter of welded pipe, mm.
Table 4.0.7.1
Wall thickness series
Water pressure test pressure, MPa
4.0.7.2 During the water pressure test, the specified test pressure shall be maintained for more than 5s, and no leakage shall occur on the pipe wall. After the water pressure test, the accumulated water in the pipe shall be removed. 4.0.7.3 With the agreement of both parties, non-destructive inspection methods may be used to replace the water pressure test of welded pipes. The specific methods and qualified indicators shall be agreed upon by both parties. 4.0.8 Eddy current flaw detection and radiographic flaw detection
The welds of welded pipes shall be subjected to full-length eddy current flaw detection. The defect display signal shall not be greater than the artificial defect signal of the GB7735A-level comparison sample. The flaw detection method shall use a through-type coil as much as possible, and a fan-shaped coil may also be used when the diameter of the welded pipe is large. The welds of welded pipes with a nominal wall thickness greater than 6.3mm shall also be subjected to partial radiographic flaw detection in accordance with GB3323. The inspection length is for each welder, and 150mm of each 15m weld shall be subjected to radiographic flaw detection, and the class is qualified.
mS test method
The test method of welded pipe shall be in accordance with the provisions of Table 5.
Melt analysis
Tensile test
Fan pressure test
Hydraulic test
Fluorescence detection
Radiographic detection
Outer diameter, wall thickness and length
Surface quality
Quantity and location of sampling
One for each furnace number (raw material warranty certificate can be used) One for each batch. When each batch is greater than 100 pieces, take two for each batch of 20 pieces, make one, but no less than two for each piece
Full length of weld
Local length of weld
Test method
GB 241
GB 7735-A
GB3323-
Note: Steel pipes produced with the same furnace number, the same outer diameter and thickness, and the same heat treatment system are considered as a batch. The number of "roots" in the tensile and flattening tests is the number of "roots" before cutting. .41
Inspection rules
6.0.1 Welded pipes shall be inspected in batches, and each batch shall consist of steel pipes with the same furnace number, the same specification and the same heat treatment system.
6.0.2 The number of samples to be taken for each inspection shall be in accordance with the provisions of Table 5. The re-inspection and judgment of welded pipes shall be in accordance with the provisions of GB2102. 6.0.3
7 Packaging, marking and quality certificate
The packaging, marking and quality certificate of welded pipes shall be in accordance with the provisions of GB2102. 7.0.1
7.0.2 Steel stamps shall not be used on welded pipes, and the printed ink or paint shall not contain any harmful metals and metal salts, such as lead, zinc, copper, etc. 7.0.3 The marking content of welded pipes shall comply with the provisions of 5.0.1 in HG20537.1. 43
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