Some standard content:
GB17268—1998
This standard adopts part of DOT39 specification 178.65 of Part 49 of the Code of Federal Regulations (1991 edition) of the United States
and part of ISO/DIS11118 "Non-refillable Metal Cylinders - Technical Requirements and Test Methods" (1995). Appendix A and Appendix B of this standard are standard appendices. Appendix C of this standard is a suggestive appendix.
This standard is proposed by the Ministry of Labor of the People's Republic of China. This standard is technically managed by the National Technical Committee for Standardization of Gas Cylinders. The drafting units of this standard are: Juhua Group Engineering Co., Ltd., Guangdong Weiguo Machinery Factory. The main drafters of this standard are: Fang Changqing, Huang Haoquan, Wu Yijiang, and Ye Qinghua. 659
1 Scope
National Standard of the People's Republic of China
Non-refillable steel welded cylinder for industry cylinder
Non-refillable steel welded cylinder for industry cylinderGB17268—1998
This standard applies to steel welded gas cylinders (hereinafter referred to as cylinders) with a test pressure of no more than 3.5MPa (gauge pressure) and a volume of 5~25L for non-refillable low-pressure liquefied gas used at an ambient temperature of -20℃:～55℃. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. GB228--87Metal tensile test method
GB232-88Metal bending test method
General tolerancesEnd-note tolerances for linear dimensions
GB/T 1804--92
GB/T3181--1995Coating color standard
GB5213--85Cold rolled thin steel sheets and strips for deep drawingTerminology for gas cylinders
GB/T 13005-91
GB14193--93Liquefied gas cylinder filling regulations3Terms and symbols
3.1Terms
Terms not defined in this standard shall be in accordance with the provisions of GB/T13005. 3.1.1Test pressure
Pressure used to calculate the wall thickness of steel cylinders and to conduct pressure tests on steel cylinders. 3.1.2 Batch
refers to the limited number of cylinders produced continuously with the same design, the same grade of material, the same welding process, and the same forming process. 3.2 Symbols
D, inner diameter of cylinder, mm;
outer diameter of cylinder, mm;
design wall thickness of cylinder, mm;
S, nominal wall thickness of cylinder, mm;
difference between the maximum and minimum diameters of the same section of cylinder, mm; E height of the angular angle of the annular seam, mm;
Pr test pressure of cylinder, MPa;
bursting pressure of cylinder body, MPa;||t t||［o］Allowable design stress of bottle body, MPa;
Approved by the State Administration of Technical Supervision on March 20, 1998, 660
Implemented on October 1, 1998
OP tensile strength of material, MPa;
GB17268--1998
Nominal yield strength when plastic strain is 2/1000, MPa; Qo.2
Yuan△D. Circumference tolerance, mm;
H height of half bottle body, mm;
AH half bottle body height tolerance, mm;
elliptical head inner surface height, mm;
inner spherical radius of dished head, mm;
inner radius of corner of transition zone of dished head, mm. Basic parameters and types
4.1 The medium suitable for filling non-Huifu filling cylinders, test pressure and cylinder color varieties shall be as specified in Table 1. 4.2 The color of the cylinder shall comply with the provisions of GB/T3181. 4.3 The maximum allowable filling coefficient of the medium shall comply with the provisions of GB14193. Table 1 Suitable filling media, test pressure and cylinder color variety Medium name
Trifluorochloroethane (R142b), dichloro-fluoromethane (R21), difluorochlorobromomethane (R12B1), trifluorochloroethane, n-butane, isobutane
Chlorofluoromethane (R12), fluoroethane
(R152a)
Cyclorene, trichlorodifluoromethane/difluoroethane (R500), tetrafluoroethane (R134a)
Fluoropentafluoroethane (R115)
Chlorodifluoromethane (R22)
Monochlorodifluoromethane/pentafluorochloroethane (R502) Trifluoroethane (R143)
4.4 See Figure 1 for the type.
Test pressure (gauge pressure), MPa
(not less than)
1--lower cylinder body; 2-upper cylinder body; 3-cylinder valve; 4-handle; 5-bursting disc Figure 1 Cylinder type
5 Material
Cylinder color variety
Sky iron blue
Bean green
5.1 The cylinder body material is 08A1 in accordance with the requirements of GB5213. When other materials are used, their performance must be similar to 08A1 and meet the relevant requirements of GB5213.
GB 17268-1998
5.2 All parts welded to the cylinder body must be made of materials that are compatible with the weldability of the cylinder body material. 5.3 The tensile strength of the weld welded by the welding material used shall not be lower than the lower limit of the specified value of the tensile strength of the parent material. 5.4 Materials (including welding materials) shall comply with the provisions of the relevant standards and must have a quality certificate. 5.5 The chemical composition of the bottle body material shall be verified according to the furnace number, and the mechanical properties shall be verified according to the batch number. 6 Design
6.1 General provisions
6.1.1 The cylinder body consists of two parts, the upper and lower bodies, with only one circumferential weld. 6.1.2 The internal pressure based on the design is the test pressure. 6.1.3 The allowable design stress of the bottle body is not greater than 310MPa. 6.2 The shape of the head should be elliptical or dish-shaped and meet the following conditions: a) Elliptical head hi≥0.2D:;
b) Dishevelled head R;≤D, r≥0.15Di. 6.3 The ratio of the height H of the half-bottle body to the inner diameter D. of the bottle body H/D: not less than 0.3. 6.4 The design wall thickness S of the bottle body is the larger of the following two: a) The design wall thickness of the bottle body is calculated according to the following formula:
b) The design wall thickness S of the bottle body should meet the following requirements: S≥D./650 + 0.5 (mm)
6.5 The determination of the nominal wall thickness of the steel cylinder should also consider the negative deviation of the steel plate and the process thinning amount. The maximum nominal wall thickness of the steel cylinder should be ≤1.5mm. 6.6 Bottle body openings
6.6.1 Reinforcement should be considered for the openings of the bottle body. The reinforcement material should be compatible with the bottle body material and have good weldability. 6.6.2 The openings of the bottle body are only allowed to be made on the head. All openings and reinforcements should be arranged within the range of an imaginary cylinder with the axis of the head as the axis and a diameter of 80% of the head diameter. 6.7 Welding joints
The circumferential weld of the bottle body must adopt the type of butt joint of the integral gasket of the bottle body. 6.8 Bottle valve
6.8.1 A non-refillable bottle valve must be used, and the bottle valve and the bottle body are connected by welding to ensure the non-reusability of the cylinder. 6.8.2 The bottle valve shall comply with the provisions of GB17878 ".I Industry Non-Refillable Bottle Valve". 6.9 Bursting disc
6.9.1 The cylinder must be equipped with a bursting disc. The bursting disc shall comply with the provisions of the relevant standards. The bursting disc model and license number shall be stamped on the bursting disc. 6.9.2 The safe discharge area of the bursting disc shall not be less than 0.17mm2 per liter of cylinder volume. 6.9.3 The bursting pressure of the bursting disc shall be in the range of 1.05Pr~1.60Pl. 7 Design finalization
7.1 Type test
Type test must be carried out for each new design of steel cylinder. For detailed provisions of type test, see Appendix A (Standard Appendix). 7.2 New design
Compared with existing steel cylinders, the pressure-bearing components of the steel cylinder shall be considered as a new design of the steel cylinder as long as they meet one of the following conditions: a) different materials are used;
b) the shape of the steel cylinder is changed;
c) the length of the steel cylinder changes by more than 50%;
d) the diameter changes by more than 5% of the original diameter;
e) the wall thickness of the cylinder changes.
7.3 Test report
GB 17268 -1998
7.3.1 The report of type test must include all the items required in Appendix A. In addition, it should also include the measured values of mechanical properties, chemical composition and wall thickness of the raw materials.
7.3.2 The manufacturer shall keep the type test report during the production period of the designed cylinder and shall keep it for 5 years after the production is stopped. 8 Manufacturing
8.1 Welding procedure qualification and test methods
Welding procedure qualification and test methods shall be carried out in accordance with the requirements of Appendix B (Standard Appendix) of this standard. 8.2 General provisions for welding
8.2.1 The welding of steel cylinders shall be undertaken by certified welders who have passed the examination in accordance with the requirements of Appendix C (Suggested Appendix) or corresponding regulations. 8.2.2 The welding of the main weld of the steel cylinder must strictly comply with the qualified welding process. 8.2.3 The welding of the main weld of the steel cylinder shall be carried out by automatic welding method. 8.2.4 The welded joint shall comply with the requirements of the drawing. The groove surface shall be clean and smooth, and shall not have defects such as cracks, delamination and inclusions. 8.2.5 Welding (including repair welding) shall be carried out indoors. If there are no effective protective measures, the relative humidity shall not be greater than 90%. 8.2.6 When welding, arc shall not be struck at non-welding locations. 8.3 Weld
The residual height of the circumferential weld of the bottle body is 0.5~2mm, and the difference between the widest and narrowest parts of the circumferential weld should not be greater than 2mm. 8.3.1
8.3.2The height of the weld leg of the fillet weld should comply with the requirements of the drawing. 8.3.3The appearance of the weld surface should comply with the following requirements: a) The weld and heat-affected zone shall not have defects such as cracks, pores, isolated pits, slag inclusions and unfused welds; b) The circumferential weld is not allowed to undercut, and the welds of the parts welded to the bottle body are not allowed to undercut on the bottle body side; c) The weld surface shall not have depressions or irregular mutations; d) The spatter on both sides of the weld must be cleaned. 8.4 Repair of welds
If pinhole leakage occurs at the main weld, only one repair is allowed, and other defects are not allowed to be repaired. 8.5 Bottle
8.5.1 The upper and lower bottle bodies must be formed by cold stamping with a whole piece of steel plate. 8.5.2 The shape tolerance and size tolerance of the bottle body shall not exceed the provisions of Table 2. Table 2
Circumference tolerance D.
Maximum and minimum diameter difference e
8.5.3 The measured wall thickness of the bottle body shall not be less than the designed wall thickness of the bottle body. 8.5.4 There shall be no wrinkles on the bottle body.
8.6 Limit deviation of dimensions without tolerances
The limit deviation of dimensions without tolerances shall comply with the provisions of GB/T1804. The specific requirements are as follows:
a) Machined parts shall comply with GB/T1804-m;
b) Non-machined parts shall comply with GB/T1804-c. Half-bottle height tolerance AH
8.7 Assembly
GB 17268 ---1998
8.7.1 The pressure-bearing components of the cylinder shall be visually inspected before assembly, and those that fail to meet the requirements shall not be assembled. 8.7.2 The inside of the cylinder should be clean, oil-free and water-free. 8.7.3 The height E of the edge angle of the circumferential weld of the cylinder should not be greater than 1mm, and the length of the inspection ruler should not be less than 200mm. 8.7.4 The assembly of spare parts should comply with the requirements of the drawings. 9 Inspection rules and test methods
9.1 Inspection of each piece
9.1.1 Appearance inspection
9.1.1.1 The surface of the cylinder should be smooth, without defects such as cracks, heavy skin, roughness, pits with a depth exceeding 0.5mm, scratches and corrosion with a depth exceeding 0.1mm.
9.1.1.2 The appearance of the weld shall comply with the provisions of 8.3.3 9.1.1.3 The valve of the cylinder shall comply with the provisions of 6.8, and the other accessories shall comply with the requirements of the drawings 9.1.2 Air pressure test
9.1.2.1 During the air pressure test, two calibrated pressure gauges with the same range and accuracy not less than Class 1.5 must be used. The range of the pressure gauge is 1.5 to 3 times the test pressure, and the calibration period of the pressure gauge shall not exceed 3 months. 9.1.2.2 The test environment temperature shall not be lower than 5℃. 9.1.2.3 During the test, the pressure shall rise slowly, the cylinder shall be pressurized for not less than 2 minutes, the pressure shall be maintained for 1 minute, and then a leak check shall be carried out. 9.1.2.4 The leak check of the cylinder shall be carried out by immersing the entire cylinder in water. 9.1.2.5 If the cylinder undergoes macroscopic deformation during the air pressure test, the cylinder shall be scrapped. 9.1.2.6 During the air pressure test, the steel plate shall be used to reliably isolate the steel cylinder from the operator to ensure the safety of the operator. 9.1.3 The steel cylinder that has been repaired shall be re-tested according to the requirements of 9.1.2. 9.2 Batch inspection
9.2.1 A steel cylinder shall be randomly selected from a batch of no more than 500 for the water pressure burst test. 9.2.2 Water pressure burst test
9.2.2.1 The following data shall be measured during the water pressure burst test: a) water volume of the steel cylinder;
b) burst pressure Pb of the steel cylinder.
9.2.2.2 The hourly water delivery of the water pump for the water pressure burst test shall generally be 1 to 2 times the volume of the steel cylinder. 9.2.2.3 The water volume of the steel cylinder shall be measured before the water pressure burst test. 9.2.2.4 When conducting a hydraulic burst test, the air in the cylinder should be exhausted first, and then the pressure should be increased slowly until the cylinder bursts. 9.2.2.5 The hydraulic burst pressure of the cylinder should not be less than 1.8 times the test pressure, otherwise the hydraulic burst test is unqualified. 9.2.2.6 The rupture of the cylinder should occur in the cylindrical part of the cylinder body, and should not first crack in the weld part. If the rupture first occurs in the weld or in the non-longitudinal direction of the head, any opening, reinforcement, pipe part, and the cylindrical part of the cylinder body, the hydraulic burst test of the cylinder is unqualified.
9.3 Repeat test
9.3.1 If the test items are unqualified one by one, they can be tested again after treatment or repair. If they still fail, they will be scrapped. 9.3.2 When conducting the test, if there is evidence that it is an operational error or measurement error, a second test should be conducted on the same cylinder or in the same batch of cylinders. If the second test is qualified, the first test can be ignored. 9.3.3 If the hydraulic burst test fails, double sample bottles can be randomly selected from the batch of cylinders for re-testing. If one sample bottle fails during the re-testing, the batch of cylinders should be scrapped. 664
10 Marking, coating, packaging, transportation, storage 10.1 Marking
GB 17268-1998
10.1.1 Cylinders should be marked by screen printing or similar methods. The marking should be clear, durable, waterproof and should not damage the cylinder body. 10.1.2 The marking contents are as follows:
a) Non-refillable cylinder;
b) Test pressure;
c) Contained medium, maximum filling volume;
d) Batch number, manufacturing date (if the batch number cannot reflect the manufacturing date); e) Manufacturing license number of the manufacturer;
f) It shall not be exposed to the sun or stored in an environment with a temperature higher than 55℃ and lower than -20℃; g) Statement: It is strictly forbidden to refill and use, otherwise the filler shall bear legal responsibility for the possible accidents. h) Cylinder weight: KG (keep the decimal place.) 10.2 Cylinders can only be coated after passing the inspection and removing the oil, rust, oxide scale, welding spatter and other debris on the surface and keeping it dry.
10.3 The cylinders shipped out of the factory should be packaged according to the requirements of the agreement signed with the user. If the user has no requirements, they should be packaged in cartons. 10.4 Steel cylinders should be protected from collision and scratches during transportation, loading and unloading. 10.5 Steel cylinders should be stored in a place without corrosive gases, ventilated, dry and not exposed to sunlight. 11 Product certificate and quality certificate
11.1 Each steel cylinder shipped out of the factory should have a product certificate, and the content recorded in the product certificate should be consistent with the production inspection records kept by the manufacturer.
11.2 Each batch of steel cylinders shipped out of the factory should provide a batch quality certificate. 665
A1 Scope
GB 17268 -1998
Appendix A
(Appendix to the standard)
Type test items and evaluation basis
This appendix gives the type test items and evaluation basis that the newly designed cylinders need to complete to meet the requirements of this standard. A2 Materials
The materials must have a warranty. The materials used for type test cylinders must be retested, and the retest results must meet the requirements of GB5213. A3 Tensile test
A3.1 Tensile specimens must be cut from 3 randomly selected type test cylinders. Take three specimens from each cylinder, a total of nine specimens. The sampling positions are shown in Figure A1.
2 for the bottle body and 1 for the weld
Figure A1 Sample sampling position
A3.2 Sample preparation and tensile test shall comply with the provisions of national standards. Bottle body samples are required to measure αo.2 and, weld seam samples are required to measure bcA3.3 Evaluation basis for tensile test:
a) Bottle body samples are not less than 430MPa;
b) Bottle body samples ao.2 are not less than 390MPa; c) Weld seam samples α are not less than 255MPa.
A4 Inspection of fillet welds between valve body and bottle body, and inspection of welds between bursting disc and bottle bodyA4.1 Inspection items include appearance inspection and metallographic inspection (macroscopic), the number of specimens is one, and 4 specimens are cut from the specimen in four equal parts, and any two inspection surfaces shall not be the two side surfaces of the same cut. A4.2 Evaluation basis
a) Visual inspection: There shall be no cracks and lack of fusion on the surface of the joint of the fillet weld test piece, and there shall be no penetration and lack of penetration on the surface of the joint of the convex weld test piece.
GB 17268 --1998
b) Metallographic inspection (macroscopic) The root of the weld shall be fully penetrated, and there shall be no cracks and lack of fusion in the weld metal and heat-affected zone. A5 Dimension inspection
A5.1 Cut the bottle body into two halves along the longitudinal direction, measure the wall thickness data, and determine the minimum wall thickness of the bottle body. The minimum wall thickness shall not be less than the designed wall thickness.
A5.2 Check whether the diameter, height, and head size of the steel cylinder meet the requirements of the drawing. A6 Burst test
A6.1 No less than three steel cylinders must be randomly sampled from the steel cylinders that have passed the gas pressure test for the burst test. A6.2 The tare weight and water volume of each steel cylinder must be measured and recorded. A6.3 The burst test and evaluation basis of the steel cylinder shall be in accordance with the provisions of 9.2.2. A7 Tenderness test
A7.1 At least one steel cylinder must be randomly sampled from the steel cylinders that have passed the air pressure test for the flattening test. A7.2 The middle of the steel cylinder is placed between two pressure heads perpendicular to the axis of the bottle body for testing. The pressure head top angle is 60°, the top circle radius is 13mm, the pressure head length is not less than 1.5 times the outer diameter D of the test bottle, the pressure head height is not less than 0.5 times the outer diameter D of the test bottle, and the pressure head surface roughness is not less than. wwW.bzxz.Net
A7.3 Under the action of load, flatten the steel cylinder until the distance between the tops of the two pressure heads is 6 times the wall thickness of the bottle body. Check that the steel cylinder is qualified if there is no crack at the flattened part.
A8 Drop test
A8.1 At least three steel cylinders must be randomly sampled from the steel cylinders in the final delivery packaging state for the drop test. A8.2 The impact surface must be a single cast concrete surface of 1 m2 area and 0.1 m thick, covered with a 0.6 m area and 25 mm thick cotton fiber phenolic resin laminate with a Brinell hardness of 45 HB and a surface flatness of no more than 2 mm difference in horizontal height between any two points on the surface. The pad must be replaced regularly and replaced promptly if it is significantly damaged during use. A8.3 The cylinder must be filled with water before testing, but it must not be tested with internal pressure. The drop test procedure is as follows: a) A cylinder is impacted from a height of 1.2 m with its bottom facing down on a ground that meets the requirements of A8.2, as shown in Figure A2a); b) A cylinder is impacted from a height of 1.2 m with its body facing down on a ground that meets the requirements of A8.2, as shown in Figure A2b); c) A cylinder is impacted from a height of 1.2 m with its valve-head facing down, with the axis of the body at a 45° angle to the ground, on a ground that meets the requirements of A8.2, as shown in Figure A2c).
A8.4 Evaluation Basis
a) Cylinders subjected to the tests required by A8.3 a) and b) shall not leak and shall pass the burst test required by 9.2.2; b) Cylinders subjected to the tests required by A8.3 c) shall not leak, and their valves shall still function normally and pass the burst test required by 9.2.2.
GB17268
3—1998
Surface that meets the requirements of A8.2
777777777777777777777777777777777777777777772 Concrete
B1 Scope of application
Figure A2 Drop test
Appendix B
(Appendix to the standard)
Welding procedure qualification
Applicable only to non-refillable steel welded gas cylinders (hereinafter referred to as cylinders). B1.1 Before manufacturing, the welding procedure qualification of cylinders shall be carried out in accordance with this appendix. c)
B1.2 This appendix specifies the welding procedure qualification rules, test methods and qualified indicators for the welds between the main pressure-bearing components of cylinders. B2 General Rules
B2.1 The welding procedure qualification process is: prepare a welding procedure instruction, weld test pieces, inspect test pieces and specimens according to the provisions of this appendix, determine whether the welded joint has the required performance, and submit a welding procedure qualification report to verify the correctness of the proposed welding procedure.
B2.2 The welding procedure qualification results shall be reviewed and approved by the factory technical director and stored in the factory technical archives. B3 Rules for welding procedure qualification
B3.1 The welding procedure qualification is carried out directly on the cylinder body. B3.2 The welding procedure qualification must be re-evaluated if the material (parent material, welding material) is changed. B3.3 The welding procedure qualification must be re-evaluated if the welding method or welding process parameters (including current, voltage range, mixed gas ratio, change from forward tilt to rearward tip, wire diameter, welding speed, weld structure) are changed. B3.4 The welding process of the qualified butt weld test piece is applicable to the effective range of the weldment base metal thickness, the maximum value is the test piece thickness, and the minimum value is 0.75 times the test piece thickness.
B4 Test piece, test piece and inspection
B4.1 Test piece preparation
GB 17268-1998
B4.1.1 The welding of base metal, welding materials, groove and test piece must comply with the requirements of the welding process instruction book. B4.1.2 The number and size of the test piece shall meet the requirements of the test piece preparation, and generally one test piece is taken. B4.2 Inspection of butt weld test pieces and test pieces B4.2.1 The inspection items are appearance inspection, mechanical property test and metallographic inspection (macroscopic). a) Appearance inspection The surface of the test piece joint shall not have cracks, incomplete penetration and incomplete fusion. b) Mechanical property test items include tensile test and bending (face bending, back bending) test, and the inspection requirements are in accordance with B4.4. c) Metallographic inspection (macroscopic) Inspection requirements are in accordance with A4.5. B4.2.2 The number of specimens for mechanical property test and metallographic test shall comply with the provisions of Table B1. Table B1
Tensile test
Tensile specimen
Face bend specimen
B4.3 Inspection of fillet weld specimens and specimens
Bending test
Back bend specimen
B4.3.1 The inspection items are appearance inspection and metallographic inspection (macroscopic). a) Appearance inspection: There shall be no cracks and lack of fusion on the surface of the specimen joint. b) Metallographic inspection (macroscopic) shall comply with the provisions of B4.5. B4.3.2 The number of specimens is 1, and 4 specimens are taken from each specimen. B4.4 Mechanical property test
B4.4.1 Sampling position
Butt welds shall be sampled according to Figure B1.
1-Tensile test specimen; 2-face bending test specimen; 3-back bending test specimen; 4-metallographic test specimen Figure B1 Sampling location diagram of butt weld
B4.4.2 Tensile test
B4.4.2.1 See Figure B2 for the test specimen form.
Low magnification metallographic test
Low magnification metallographic test specimen
B4.4.2.2 Test method
GB17268
Figure B2 Tensile test specimen
Tensile test The tensile strength of the welded joint shall be determined according to the test method specified in GB228. B4.4.2.3 Qualified index
The tensile strength of each specimen shall not be less than the lower limit of the value specified in the standard of the parent steel grade. B4.4.3 Bending test
B4.4.3.1 See Figure B3 for the test specimen form.
Figure B3 Bending test specimen
Note: The weld excess and pad of the specimen shall be removed by machining. The tensile surface of the face bending and back bending specimens shall be flush and retain the original surface of the parent material. B4.4.3.2 Test method
The bending test shall be carried out in accordance with the test method specified in GB232 and Table B2 to determine the compactness and plasticity of the welded joint. Table B2
Bending axis diameter
B4.4.3.3 Qualified index
Distance between supports
Bending angle
After the specimen is bent to the specified angle, its tensile surface shall not have cracks or defects in any direction, otherwise it shall be unqualified. B4.5 Metallographic examination (macroscopic)
B4.5.1 Sampling method
One specimen shall be taken for evaluation at one time. Four specimens shall be cut from each specimen in four equal parts. One surface of each specimen shall be taken for metallographic examination. Any two inspection surfaces shall not be the two side surfaces of the same cut. B4.5.2 Qualified indicators
The weld root should be fully penetrated, and there should be no cracks or lack of fusion in the weld metal and heat affected zone. 6702. A7 Tenderness test
A7.1 At least one cylinder must be randomly sampled from the cylinders that have passed the air pressure test for the flattening test. A7.2 Place the middle of the cylinder between two pressure heads perpendicular to the axis of the bottle body for testing. The pressure head top angle is 60°, the top circle radius is 13mm, the pressure head length is not less than 1.5 times the outer diameter D of the test bottle, the pressure head height is not less than 0.5 times the outer diameter D of the test bottle, and the pressure head surface roughness is not less than.
A7.3 Under load, flatten the cylinder until the distance between the tops of the two pressure heads is 6 times the wall thickness of the bottle body. Check that the cylinder is qualified if there is no crack at the flattened part.
A8 Drop test
A8.1 At least three cylinders must be randomly sampled from the cylinders in the final delivery packaging state for the drop test. A8.2 The impact surface must be a single cast concrete surface of 1 m2 area and 0.1 m thick, covered with a 0.6 m area and 25 mm thick cotton fiber phenolic resin laminate with a Brinell hardness of 45 HB and a surface flatness of no more than 2 mm difference in horizontal height between any two points on the surface. The pad must be replaced regularly and replaced promptly if it is significantly damaged during use. A8.3 The cylinder must be filled with water before testing, but it must not be tested with internal pressure. The drop test procedure is as follows: a) A cylinder is impacted from a height of 1.2 m with its bottom facing down on a ground that meets the requirements of A8.2, as shown in Figure A2a); b) A cylinder is impacted from a height of 1.2 m with its body facing down on a ground that meets the requirements of A8.2, as shown in Figure A2b); c) A cylinder is impacted from a height of 1.2 m with its valve-head facing down, with the axis of the body at a 45° angle to the ground, on a ground that meets the requirements of A8.2, as shown in Figure A2c).
A8.4 Evaluation Basis
a) Cylinders subjected to the tests required by A8.3 a) and b) shall not leak and shall pass the burst test required by 9.2.2; b) Cylinders subjected to the tests required by A8.3 c) shall not leak, and their valves shall still function normally and pass the burst test required by 9.2.2.
GB17268
3—1998
Surface that meets the requirements of A8.2
777777777777777777777777777777777777777777772 Concrete
B1 Scope of application
Figure A2 Drop test
Appendix B
(Appendix to the standard)
Welding procedure qualification
Applicable only to non-refillable steel welded gas cylinders (hereinafter referred to as cylinders). B1.1 Before manufacturing, the welding procedure qualification of cylinders shall be carried out in accordance with this appendix. c)
B1.2 This appendix specifies the welding procedure qualification rules, test methods and qualified indicators for the welds between the main pressure-bearing components of cylinders. B2 General Rules
B2.1 The welding procedure qualification process is: prepare a welding procedure instruction, weld test pieces, inspect test pieces and specimens according to the provisions of this appendix, determine whether the welded joint has the required performance, and submit a welding procedure qualification report to verify the correctness of the proposed welding procedure.
B2.2 The welding procedure qualification results shall be reviewed and approved by the factory technical director and stored in the factory technical archives. B3 Rules for welding procedure qualification
B3.1 The welding procedure qualification is carried out directly on the cylinder body. B3.2 The welding procedure qualification must be re-evaluated if the material (parent material, welding material) is changed. B3.3 The welding procedure qualification must be re-evaluated if the welding method or welding process parameters (including current, voltage range, mixed gas ratio, change from forward tilt to rearward tip, wire diameter, welding speed, weld structure) are changed. B3.4 The welding process of the qualified butt weld test piece is applicable to the effective range of the weldment base metal thickness, the maximum value is the test piece thickness, and the minimum value is 0.75 times the test piece thickness.
B4 Test piece, test piece and inspection
B4.1 Test piece preparation
GB 17268-1998
B4.1.1 The welding of base metal, welding materials, groove and test piece must comply with the requirements of the welding process instruction book. B4.1.2 The number and size of the test piece shall meet the requirements of the test piece preparation, and generally one test piece is taken. B4.2 Inspection of butt weld test pieces and test pieces B4.2.1 The inspection items are appearance inspection, mechanical property test and metallographic inspection (macroscopic). a) Appearance inspection The surface of the test piece joint shall not have cracks, incomplete penetration and incomplete fusion. b) Mechanical property test items include tensile test and bending (face bending, back bending) test, and the inspection requirements are in accordance with B4.4. c) Metallographic inspection (macroscopic) Inspection requirements are in accordance with A4.5. B4.2.2 The number of specimens for mechanical property test and metallographic test shall comply with the provisions of Table B1. Table B1
Tensile test
Tensile specimen
Face bend specimen
B4.3 Inspection of fillet weld specimens and specimens
Bending test
Back bend specimen
B4.3.1 The inspection items are appearance inspection and metallographic inspection (macroscopic). a) Appearance inspection: There shall be no cracks and lack of fusion on the surface of the specimen joint. b) Metallographic inspection (macroscopic) shall comply with the provisions of B4.5. B4.3.2 The number of specimens is 1, and 4 specimens are taken from each specimen. B4.4 Mechanical property test
B4.4.1 Sampling position
Butt welds shall be sampled according to Figure B1.
1-Tensile test specimen; 2-face bending test specimen; 3-back bending test specimen; 4-metallographic test specimen Figure B1 Sampling location diagram of butt weld
B4.4.2 Tensile test
B4.4.2.1 See Figure B2 for the test specimen form.
Low magnification metallographic test
Low magnification metallographic test specimen
B4.4.2.2 Test method
GB17268
Figure B2 Tensile test specimen
Tensile test The tensile strength of the welded joint shall be determined according to the test method specified in GB228. B4.4.2.3 Qualified index
The tensile strength of each specimen shall not be less than the lower limit of the value specified in the standard of the parent steel grade. B4.4.3 Bending test
B4.4.3.1 See Figure B3 for the test specimen form.
Figure B3 Bending test specimen
Note: The weld excess and pad of the specimen shall be removed by machining. The tensile surface of the face bending and back bending specimens shall be flush and retain the original surface of the parent material. B4.4.3.2 Test method
The bending test shall be carried out in accordance with the test method specified in GB232 and Table B2 to determine the compactness and plasticity of the welded joint. Table B2
Bending axis diameter
B4.4.3.3 Qualified index
Distance between supports
Bending angle
After the specimen is bent to the specified angle, its tensile surface shall not have cracks or defects in any direction, otherwise it shall be unqualified. B4.5 Metallographic examination (macroscopic)
B4.5.1 Sampling method
One specimen shall be taken for evaluation at one time. Four specimens shall be cut from each specimen in four equal parts. One surface of each specimen shall be taken for metallographic examination. Any two inspection surfaces shall not be the two side surfaces of the same cut. B4.5.2 Qualified indicators
The weld root should be fully penetrated, and there should be no cracks or lack of fusion in the weld metal and heat affected zone. 6702. A7 Tenderness test
A7.1 At least one cylinder must be randomly sampled from the cylinders that have passed the air pressure test for the flattening test. A7.2 Place the middle of the cylinder between two pressure heads perpendicular to the axis of the bottle body for testing. The pressure head top angle is 60°, the top circle radius is 13mm, the pressure head length is not less than 1.5 times the outer diameter D of the test bottle, the pressure head height is not less than 0.5 times the outer diameter D of the test bottle, and the pressure head surface roughness is not less than.
A7.3 Under load, flatten the cylinder until the distance between the tops of the two pressure heads is 6 times the wall thickness of the bottle body. Check that the cylinder is qualified if there is no crack at the flattened part.
A8 Drop test
A8.1 At least three cylinders must be randomly sampled from the cylinders in the final delivery packaging state for the drop test. A8.2 The impact surface must be a single cast concrete surface of 1 m2 area and 0.1 m thick, covered with a 0.6 m area and 25 mm thick cotton fiber phenolic resin laminate with a Brinell hardness of 45 HB and a surface flatness of no more than 2 mm difference in horizontal height between any two points on the surface. The pad must be replaced regularly and replaced promptly if it is significantly damaged during use. A8.3 The cylinder must be filled with water before testing, but it must not be tested with internal pressure. The drop test procedure is as follows: a) A cylinder is impacted from a height of 1.2 m with its bottom facing down on a ground that meets the requirements of A8.2, as shown in Figure A2a); b) A cylinder is impacted from a height of 1.2 m with its body facing down on a ground that meets the requirements of A8.2, as shown in Figure A2b); c) A cylinder is impacted from a height of 1.2 m with its valve-head facing down, with the axis of the body at a 45° angle to the ground, on a ground that meets the requirements of A8.2, as shown in Figure A2c).
A8.4 Evaluation Basis
a) Cylinders subjected to the tests required by A8.3 a) and b) shall not leak and shall pass the burst test required by 9.2.2; b) Cylinders subjected to the tests required by A8.3 c) shall not leak, and their valves shall still function normally and pass the burst test required by 9.2.2.
GB17268
3—1998
Surface that meets the requirements of A8.2
777777777777777777777777777777777777777777772 Concrete
B1 Scope of application
Figure A2 Drop test
Appendix B
(Appendix to the standard)
Welding procedure qualification
Applicable only to non-refillable steel welded gas cylinders (hereinafter referred to as cylinders). B1.1 Before manufacturing, the welding procedure qualification of cylinders shall be carried out in accordance with this appendix. c)
B1.2 This appendix specifies the welding procedure qualification rules, test methods and qualified indicators for the welds between the main pressure-bearing components of cylinders. B2 General Rules
B2.1 The welding procedure qualification process is: prepare a welding procedure instruction, weld test pieces, inspect test pieces and specimens according to the provisions of this appendix, determine whether the welded joint has the required performance, and submit a welding procedure qualification report to verify the correctness of the proposed welding procedure.
B2.2 The welding procedure qualification results shall be reviewed and approved by the factory technical director and stored in the factory technical archives. B3 Rules for welding procedure qualification
B3.1 The welding procedure qualification is carried out directly on the cylinder body. B3.2 The welding procedure qualification must be re-evaluated if the material (parent material, welding material) is changed. B3.3 The welding procedure qualification must be re-evaluated if the welding method or welding process parameters (including current, voltage range, mixed gas ratio, change from forward tilt to rearward tip, wire diameter, welding speed, weld structure) are changed. B3.4 The welding process of the qualified butt weld test piece is applicable to the effective range of the weldment base metal thickness, the maximum value is the test piece thickness, and the minimum value is 0.75 times the test piece thickness.
B4 Test piece, test piece and inspection
B4.1 Test piece preparation
GB 17268-1998
B4.1.1 The welding of base metal, welding materials, groove and test piece must comply with the requirements of the welding process instruction book. B4.1.2 The number and size of the test piece shall meet the requirements of the test piece preparation, and generally one test piece is taken. B4.2 Inspection of butt weld test pieces and test pieces B4.2.1 The inspection items are appearance inspection, mechanical property test and metallographic inspection (macroscopic). a) Appearance inspection The surface of the test piece joint shall not have cracks, incomplete penetration and incomplete fusion. b) Mechanical property test items include tensile test and bending (face bending, back bending) test, and the inspection requirements are in accordance with B4.4. c) Metallographic inspection (macroscopic) Inspection requirements are in accordance with A4.5. B4.2.2 The number of specimens for mechanical property test and metallographic test shall comply with the provisions of Table B1. Table B1
Tensile test
Tensile specimen
Face bend specimen
B4.3 Inspection of fillet weld specimens and specimens
Bending test
Back bend specimen
B4.3.1 The inspection items are appearance inspection and metallographic inspection (macroscopic). a) Appearance inspection: There shall be no cracks and lack of fusion on the surface of the specimen joint. b) Metallographic inspection (macroscopic) shall comply with the provisions of B4.5. B4.3.2 The number of specimens is 1, and 4 specimens are taken from each specimen. B4.4 Mechanical property test
B4.4.1 Sampling position
Butt welds shall be sampled according to Figure B1.
1-Tensile test specimen; 2-face bending test specimen; 3-back bending test specimen; 4-metallographic test specimen Figure B1 Sampling location diagram of butt weld
B4.4.2 Tensile test
B4.4.2.1 See Figure B2 for the test specimen form.
Low magnification metallographic test
Low magnification metallographic test specimen
B4.4.2.2 Test method
GB17268
Figure B2 Tensile test specimen
Tensile test The tensile strength of the welded joint shall be determined according to the test method specified in GB228. B4.4.2.3 Qualified index
The tensile strength of each specimen shall not be less than the lower limit of the value specified in the standard of the parent steel grade. B4.4.3 Bending test
B4.4.3.1 See Figure B3 for the test specimen form.
Figure B3 Bending test specimen
Note: The weld excess and pad of the specimen shall be removed by machining. The tensile surface of the face bending and back bending specimens shall be flush and retain the original surface of the parent material. B4.4.3.2 Test method
The bending test shall be carried out in accordance with the test method specified in GB232 and Table B2 to determine the compactness and plasticity of the welded joint. Table B2
Bending axis diameter
B4.4.3.3 Qualified index
Distance between supports
Bending angle
After the specimen is bent to the specified angle, its tensile surface shall not have cracks or defects in any direction, otherwise it shall be unqualified. B4.5 Metallographic examination (macroscopic)
B4.5.1 Sampling method
One specimen shall be taken for evaluation at one time. Four specimens shall be cut from each specimen in four equal parts. One surface of each specimen shall be taken for metallographic examination. Any two inspection surfaces shall not be the two side surfaces of the same cut. B4.5.2 Qualified indicators
The weld root should be fully penetrated, and there should be no cracks or lack of fusion in the weld metal and heat affected zone. 6704 Evaluation basis
a) The cylinders subjected to the test requirements of A8.3 a) and b) shall not leak and pass the burst test required by 9.2.2; b) The cylinders subjected to the test requirements of A8.3 c) shall not leak, the valves can still work normally and pass the burst test required by 9.2.2.
GB17268
3—1998
Surface that meets the requirements of A8.2
77777777777777777777777777777777777777772 Concrete
B1 Scope of application
Figure A2 Drop test
Appendix B
(Appendix to the standard)
Welding procedure qualification
Applicable only to non-refillable steel welded gas cylinders (hereinafter referred to as cylinders). B1.1 Before manufacturing, the steel cylinders shall be subjected to welding procedure qualification according to this appendix. c)
B1.2 This appendix specifies the welding procedure qualification rules, test methods and qualified indicators for the welds between the main pressure-bearing components of the steel cylinders. B2 General
B2.1 The welding procedure qualification process is: prepare a welding procedure instruction, weld test pieces, inspect test pieces and specimens according to the provisions of this appendix, determine whether the welded joints have the required performance, and submit a welding procedure qualification report to verify the correctness of the proposed welding procedure.
B2.2 The welding procedure qualification results shall be reviewed and approved by the factory's chief technical officer and stored in the factory's technical files. B3 Rules for welding procedure qualification
B3.1 The welding procedure qualification is carried out directly on the steel cylinder body. B3.2 The welding procedure qualification shall be re-qualified if the materials (parent material, welding material) are changed. B3.3 If the welding method or welding process parameters (including current, voltage range, mixed gas ratio, welding nozzle forward tilt to rearward tilt, wire diameter, welding speed, weld structure) are changed, the welding process must be re-evaluated. B3.4 The welding process of the qualified butt weld test piece is applicable to the effective range of the weld parent material thickness, the maximum value is the test piece thickness, and the minimum value is 0.75 times the test piece thickness.
B4 Test pieces, test specimens and inspection
B4.1 Test piece preparation
GB 17268-1998
B4.1.1 The welding of parent material, welding materials, groove and test piece must comply with the requirements of the welding process instruction book. B4.1.2 The number and size of the test piece shall meet the requirements for the preparation of the test specimen, and generally one test piece is taken. B4.2 Inspection of butt weld test pieces and test specimens B4.2.1 The inspection items are appearance inspection, mechanical property test and metallographic inspection (macroscopic). a) Visual inspection: There shall be no cracks, incomplete penetration and incomplete fusion on the surface of the joint of the test piece. b) Mechanical property test items include tensile test and bending (face bending, back bending) test, and the inspection requirements shall be in accordance with B4.4. c) Metallographic inspection (macroscopic) inspection requirements shall be in accordance with A4.5. B4.2.2 The number of specimens for mechanical property test and metallographic test macroscopic shall comply with the provisions of Table B1. Table B1
Tensile test
Tensile specimen
Face bending specimen
B4.3 Inspection of fillet weld specimens and specimens
Bending test
Back bending specimen
B4.3.1 The inspection items are visual inspection and metallographic inspection (macroscopic). a) Visual inspection: There shall be no cracks and incomplete fusion on the surface of the joint of the test piece. b) Metallographic inspection (macroscopic) shall be in accordance with B4.5. B4.3.2 The number of specimens is 1, and 4 specimens are taken from each specimen. B4.4 Mechanical properties test
B4.4.1 Sampling position
Butt welds shall be sampled according to Figure B1.
1-Tensile test specimen; 2-Face bending test specimen; 3-Back bending test specimen; 4-Metallographic test specimen Figure B1 Sampling position diagram of butt welds
B4.4.2 Tensile test
B4.4.2.1 The form of the test specimen is shown in Figure B2.
Low magnification metallographic test
Low magnification metallographic test specimen
B4.4.2.2 Test method
GB17268
Figure B2 Tensile test specimen
Tensile test The tensile strength of the welded joint shall be determined according to the test method specified in GB228. B4.4.2.3 Qualified index
The tensile strength of each specimen shall not be less than the lower limit of the value specified in the standard of the parent steel grade. B4.4.3 Bending test
B4.4.3.1 See Figure B3 for the specimen form.
Figure B3 Bending specimen
Note: The weld reinforcement and pad of the specimen shall be removed by machining. The tensile surface of the face bend and back bend specimens shall be flush and retain the original surface of the parent material. B4.4.3.2 Test method
The bending test shall be carried out in accordance with the test methods specified in GB232 and Table B2 to determine the compactness and plasticity of the welded joint. Table B2
Bending axis diameter
B4.4.3.3 Qualified indicators
Distance between supports
Bending angle
After the specimen is bent to the specified angle, no cracks or defects in any direction shall appear on its tensile surface, otherwise it shall be unqualified. B4.5 Metallographic inspection (macroscopic)
B4.5.1 Sampling method
One test piece shall be taken for each assessment, and 4 samples shall be cut from each test piece into four equal parts. One surface of each sample shall be taken for metallographic inspection, and any two inspection surfaces shall not be the two sides of the same cut. B4.5.2 Qualified indicators
The root of the weld shall be fully welded, and there shall be no cracks or incomplete fusion in the weld metal and heat-affected zone. 6704 Evaluation basis
a) The cylinders subjected to the test requirements of A8.3 a) and b) shall not leak and pass the burst test required by 9.2.2; b) The cylinders subjected to the test requirements of A8.3 c) shall not leak, the valves can still work normally and pass the burst test required by 9.2.2.
GB17268
3—1998
Surface that meets the requirements of A8.2
77777777777777777777777777777777777777772 Concrete
B1 Scope of application
Figure A2 Drop test
Appendix B
(Appendix to the standard)
Welding procedure qualification
Applicable only to non-refillable steel welded gas cylinders (hereinafter referred to as cylinders). B1.1 Before manufacturing, the steel cylinders shall be subjected to welding procedure qualification according to this appendix. c)
B1.2 This appendix specifies the welding procedure qualification rules, test methods and qualified indicators for the welds between the main pressure-bearing components of the steel cylinders. B2 General
B2.1 The welding procedure qualification process is: prepare a welding procedure instruction, weld test pieces, inspect test pieces and specimens according to the provisions of this appendix, determine whether the welded joints have the required performance, and submit a welding procedure qualification report to verify the correctness of the proposed welding procedure.
B2.2 The welding procedure qualification results shall be reviewed and approved by the factory's chief technical officer and stored in the factory's technical files. B3 Rules for welding procedure qualification
B3.1 The welding procedure qualification is carried out directly on the steel cylinder body. B3.2 The welding procedure qualification shall be re-qualified if the materials (parent material, welding material) are changed. B3.3 If the welding method or welding process parameters (including current, voltage range, mixed gas ratio, welding nozzle forward tilt to rearward tilt, wire diameter, welding speed, weld structure) are changed, the welding process must be re-evaluated. B3.4 The welding process of the qualified butt weld test piece is applicable to the effective range of the weld parent material thickness, the maximum value is the test piece thickness, and the minimum value is 0.75 times the test piece thickness.
B4 Test pieces, test specimens and inspection
B4.1 Test piece preparation
GB 17268-1998
B4.1.1 The welding of parent material, welding materials, groove and test piece must comply with the requirements of the welding process instruction book. B4.1.2 The number and size of the test piece shall meet the requirements for the preparation of the test specimen, and generally one test piece is taken. B4.2 Inspection of butt weld test pieces and test specimens B4.2.1 The inspection items are appearance inspection, mechanical property test and metallographic inspection (macroscopic). a) Visual inspection: There shall be no cracks, incomplete penetration and incomplete fusion on the surface of the joint of the test piece. b) Mechanical property test items include tensile test and bending (face bending, back bending) test, and the inspection requirements shall be in accordance with B4.4. c) Metallographic inspection (macroscopic) inspection requirements shall be in accordance with A4.5. B4.2.2 The number of specimens for mechanical property test and metallographic test macroscopic shall comply with the provisions of Table B1. Table B1
Tensile test
Tensile specimen
Face bending specimen
B4.3 Inspection of fillet weld specimens and specimens
Bending test
Back bending specimen
B4.3.1 The inspection items are visual inspection and metallographic inspection (macroscopic). a) Visual inspection: There shall be no cracks and incomplete fusion on the surface of the joint of the test piece. b) Metallographic inspection (macroscopic) shall be in accordance with B4.5. B4.3.2 The number of specimens is 1, and 4 specimens are taken from each specimen. B4.4 Mechanical properties test
B4.4.1 Sampling position
Butt welds shall be sampled according to Figure B1.
1-Tensile test specimen; 2-Face bending test specimen; 3-Back bending test specimen; 4-Metallographic test specimen Figure B1 Sampling position diagram of butt welds
B4.4.2 Tensile test
B4.4.2.1 The form of the test specimen is shown in Figure B2.
Low magnification metallographic test
Low magnification metallographic test specimen
B4.4.2.2 Test method
GB17268
Figure B2 Tensile test specimen
Tensile test The tensile strength of the welded joint shall be determined according to the test method specified in GB228. B4.4.2.3 Qualified index
The tensile strength of each specimen shall not be less than the lower limit of the value specified in the standard of the parent steel grade. B4.4.3 Bending test
B4.4.3.1 See Figure B3 for the specimen form.
Figure B3 Bending specimen
Note: The weld reinforcement and pad of the specimen shall be removed by machining. The tensile surface of the face bend and back bend specimens shall be flush and retain the original surface of the parent material. B4.4.3.2 Test method
The bending test shall be carried out in accordance with the test methods specified in GB232 and Table B2 to determine the compactness and plasticity of the welded joint. Table B2
Bending axis diameter
B4.4.3.3 Qualified indicators
Distance between supports
Bending angle
After the specimen is bent to the specified angle, no cracks or defects in any direction shall appear on its tensile surface, otherwise it shall be unqualified. B4.5 Metallographic inspection (macroscopic)
B4.5.1 Sampling method
One test piece shall be taken for each assessment, and 4 samples shall be cut from each test piece into four equal parts. One surface of each sample shall be taken for metallographic inspection, and any two inspection surfaces shall not be the two sides of the same cut. B4.5.2 Qualified indicators
The root of the weld shall be fully welded, and there shall be no cracks or incomplete fusion in the weld metal and heat-affected zone. 6701 Sampling position
Butt welds shall be sampled according to Figure B1.
1-Tensile test specimen; 2-Face bending test specimen; 3-Back bending test specimen; 4-Metallographic test specimen Figure B1 Butt weld sampling position diagram
B4.4.2 Tensile test
B4.4.2.1 See Figure B2 for the sample form.
Macrometallographic test
Macrometallographic test specimen
B4.4.2.2 Test method
GB17268
Figure B2 Tensile test specimen
Tensile test The tensile strength of the welded joint shall be determined according to the test method specified in GB228. B4.4.2.3 Qualified index
The tensile strength of each specimen shall not be less than the lower limit of the value specified in the standard of the parent steel grade. B4.4.3 Bend test
B4.4.3.1 See Figure B3 for the sample form.
Figure B3 Bending test specimen
Note: The weld excess and pad of the specimen shall be removed by machining. The tensile surface of the face bending and back bending specimens shall be flush and retain the original surface of the parent material. B4.4.3.2 Test method
The bending test shall be carried out in accordance with the test method specified in GB232 and Table B2 to determine the compactness and plasticity of the welded joint. Table B2
Bending axis diameter
B4.4.3.3 Qualified index
Distance between supports
Bending angle
After the specimen is bent to the specified angle, its tensile surface shall not have cracks or defects in any direction, otherwise it shall be unqualified. B4.5 Metallographic examination (macroscopic)
B4.5.1 Sampling method
One specimen shall be taken for evaluation at one time. Four specimens shall be cut from each specimen in four equal parts. One surface of each specimen shall be taken for metallographic examination. Any two inspection surfaces shall not be the two side surfaces of the same cut. B4.5.2 Qualified indicators
The weld root should be fully penetrated, and there should be no cracks or lack of fusion in the weld metal and heat affected zone. 6701 Sampling position
Butt welds shall be sampled according to Figure B1.
1-Tensile test specimen; 2-Face bending test specimen; 3-Back bending test specimen; 4-Metallographic test specimen Figure B1 Butt weld sampling position diagram
B4.4.2 Tensile test
B4.4.2.1 See Figure B2 for the sample form.
Macrometallographic test
Macrometallographic test specimen
B4.4.2.2 Test method
GB17268
Figure B2 Tensile test specimen
Tensile test The tensile strength of the welded joint shall be determined according to the test method specified in GB228. B4.4.2.3 Qualified index
The tensile strength of each specimen shall not be less than the lower limit of the value specified in the standard of the parent steel grade. B4.4.3 Bend test
B4.4.3.1 See Figure B3 for the sample form.
Figure B3 Bending test specimen
Note: The weld excess and pad of the specimen shall be removed by machining. The tensile surface of the face bending and back bending specimens shall be flush and retain the original surface of the parent material. B4.4.3.2 Test method
The bending test shall be carried out in accordance with the test method specified in GB232 and Table B2 to determine the compactness and plasticity of the welded joint. Table B2
Bending axis diameter
B4.4.3.3 Qualified index
Distance between supports
Bending angle
After the specimen is bent to the specified angle, its tensile surface shall not have cracks or defects in any direction, otherwise it shall be unqualified. B4.5 Metallographic examination (macroscopic)
B4.5.1 Sampling method
One specimen shall be taken for evaluation at one time. Four specimens shall be cut from each specimen in four equal parts. One surface of each specimen shall be taken for metallographic examination. Any two inspection surfaces shall not be the two side surfaces of the same cut. B4.5.2 Qualified indicators
The weld root should be fully penetrated, and there should be no cracks or lack of fusion in the weld metal and heat affected zone. 670
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