Some standard content:
GB 17259--1998
Liquefied petroleum gas cylinders for motor vehicles are fixed on motor vehicles and become a special part of motor vehicles. They work under the running conditions of motor vehicles. Different from civilian liquefied petroleum gas cylinders, they should belong to special steel welded gas cylinders. People are exploring fuels including natural gas and liquefied petroleum gas as gasoline substitutes. Economically developed countries have mature technologies and corresponding technical standards and policies and regulations, but there is no complete set of international standard systems in this regard. At present, China has successively introduced liquefied petroleum gas cylinders and automobile fuel devices for automobiles from the United States, Australia, Russia, South Korea, New Zealand and other countries, but their technical standards are not the same. For the above reasons, this standard does not adopt a foreign standard equivalently, but refers to ISO4706:1989 "Refillable Steel Welded Cylinders", Australia AS3509:1988 "Liquefied Petroleum Gas Cylinders for Automobiles", and the United Nations' Regulation on Special Equipment for LPG Motor Vehicles "ECE Regulation No. 67"; combined with my country's national conditions, it absorbs and adopts the mature experience of GB5100-94 "Steel Welded Cylinders" and GB5842--1996 "Liquefied Petroleum Gas Cylinders", and strives to be in line with foreign advanced standards. Appendix A and Appendix B of this standard are standard appendices, and Appendix C and Appendix D are reminder appendices. This standard was proposed by the Ministry of Labor of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee for Standardization of Gas Cylinders. This standard was drafted by Harbin Jiancheng Machinery Factory, and Guangdong Aohua Petroleum Gas Automobile Equipment Co., Ltd. and Xi'an Jiaotong University Natural Gas Automobile Research Institute participated in the drafting.
The main drafters of this standard are: Lu Yang, Xu Wencai, Liu Tiansheng, Pan Hua, Kong Xiangliu and Liu Shouzheng. 157
1 Scope
National Standard of the People's Republic of China
Steel cylinders for the liquefied petroleum gas for vehicles
Steel cylinders for the liquefied petroleum gas for vehiclesGB 17259—1998
This standard specifies the type and basic parameters, design, manufacture, test methods and inspection rules, marking and coating of steel cylinders for liquefied petroleum gas for vehicles (hereinafter referred to as vehicle cylinders). This standard is applicable to vehicle cylinders with a working environment temperature of 40℃～60℃, a nominal working pressure of 2.2MPa, a pressure test pressure of 3.3MPa, a nominal volume of 20～240L, and can be repeatedly filled with liquefied petroleum gas. The liquefied petroleum gas used shall comply with GB11174 standard, in which the sulfur content shall be controlled below 0.015 mass % and the butadiene content shall be controlled below 0.5 mol %. 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. GB150—1998 Steel pressure vessels
GB226—91 Acid etching test method for macrostructure and defects of steelGB228—87 Metal tensile test method
GB 232-—88
Metal bending test method
GB/T1804—92 Tensile test method for welded joints with general tolerance linear dimensions without tolerances
GB 2651-—89
GB 2653-—89
GB 6397—86
GB 6653—94
GB 7144-—86
Bending and flattening test method for welded joints
Metal tensile test specimen
Steel plates for welded gas cylinders
Color marking of gas cylinders
GB 8335—1998
Special thread for gas cylinders
GB/T 9251—1997
Method for hydrostatic test of gas cylinders
GB 11174—89
Liquefied petroleum gas
GB 12137-89
Method for air tightness test of gas cylinders
GB/T 13005—91
Terms for gas cylinders
GB 15384—94
Method for naming gas cylinder models
:GB 15385—94
Hydraulic burst test method for gas cylinders
JB4708---92 Welding procedure assessment for steel pressure vesselsJB4730—94 Nondestructive testing of pressure vessels
Regulations on Safety Supervision of Gas CylindersPromulgated by the Ministry of Labor in 1989Approved by the State Bureau of Technical Supervision on March 20, 1998158
Implementation on October 1, 1998
3 Definitions and symbols
3.1 Definitions
3.1.1 Batch
GB 17259—1998
Refers to the limited number of automotive steel cylinders produced continuously with the same design, same grade of material, same welding process and same heat treatment process.
3.1.2 Assembly
refers to fully assembled pressure-bearing components such as liquid level gauges and valves that are directly connected to the cylinder body with threads or bolt flanges. 3.1.3 Accessories
refers to devices directly welded to the cylinder body for the purpose of reinforcing or protecting assembly components, as well as parts used for handling, fixing and steel stamping. 3.1.4 Class A cylinders for vehicles
refers to complete vehicle cylinders that have been assembled with assembly components and accessories according to the technical requirements of the design and are provided to users (or installers). 3.1.5 Class B cylinders for vehicles
refers to vehicle cylinders that have not been assembled with assembly components according to the technical requirements of the design and are provided to users (or installers) with installation interfaces. 3.2 Symbols
gap between the curved surface of the head and the sample, mm;
b—misalignment of the weld joint, mm;
a—concave and convex amount of the head surface, mm;
d—diameter of the bending axis of the bending test, mm;
—nominal diameter, mm;
inner diameter, mm;
outer diameter, mm;
height of the angularity of the butt weld, mm;
—simplified Chinese characters with the same horizontal bar Difference between the maximum and minimum diameters of the cross-sectional area, mm; Height of the straight edge of the head, mm;
H,-—Height of the inner convex surface of the head, mm;
Form factor of a head;
Length of the bottle body (including the height of the heads at both ends), mm; -Length of the sample, mm;
Ratio of the bending axis diameter to the thickness of the sample;
Nominal working pressure, MPa;
Measured bursting pressure, MPa;
Pressure test Test pressure, MPa;
Inner radius of the corner of the transition zone of the head, mm;
Inner radius of the spherical part of the head, mm;
-Design wall thickness of the bottle body, mm,
Design wall thickness of the cylinder body, mm;
Design wall thickness of the head, mm;
Minimum measured wall thickness of the bottle body before the test, mm; -Weld width of the tensile test specimen, mm;
Thickness of the specimen, mm;
Bottle body Nominal wall thickness, mm;
Nominal volume, L;
Minimum tensile strength specified in GB17259-1998
Material standard, MPa; Actual tensile strength, MPa;
Yield stress or yield point of material at room temperature, MPa; -Height tolerance of head (Hi+h), mm; Elongation of short specimen, %;
Welding seam coefficient;
Inner circumference tolerance, mm.
4 Category, type and basic parameters
4.1 Category
It is allowed to be provided to users (installers) in two types: vehicle-use A cylinder and vehicle-use B cylinder. 4.2 The model marking method of vehicle cylinders is as follows: CYS
AAA-
Remodel serial number (Roman numerals)
Third characteristic number (nominal working pressure)
Second characteristic number (nominal volume)
First characteristic number (cylinder inner diameter)
Horizontal seam
Liquefied petroleum gas cylinder for vehicle
Model example:
Nominal working pressure 2.2MPa, nominal volume 50.2L, inner diameter $314mm, horizontal seam vehicle cylinder (Type I), its model marking is: \CYSW314-50.2-2.2-I”
4.3 Nominal volume and inner diameter
The nominal volume and inner diameter of vehicle cylinders shall be as specified in Table 1. Table 1
Nominal volume V, L
Inner diameter D
20~150
200230250280314350400
Note: The values in brackets are not recommended.
Nominal working pressure and pressure test pressure
The nominal working pressure of vehicle cylinders is 2.2MPa, and the pressure test pressure is 3.3MPa. 5 Materials
5.1 General provisions
150~240
400450500
5.1.1 All materials shall comply with the relevant standards and must have a quality certificate. 5.1.2 The main body of the vehicle cylinder (referring to the pressure-bearing components such as the head and cylinder) must be made of killed steel smelted in an open-hearth furnace, electric furnace or oxygen-blown converter, with good rolling and welding properties. The chemical composition shall comply with the provisions of GB6653. When using foreign materials, the following provisions shall be met:160
GB17259-1998
a) The material brand shall be the brand listed in the foreign pressure vessel or gas cylinder special material standard, and the technical requirements and process requirements shall not be lower than the provisions of GB6653.
b) Cold and hot processing tests, welding and heat treatment process assessments shall be carried out and corresponding technical documents shall be formulated. 5.1.3 The chemical composition of the main material of the vehicle cylinder must be verified and analyzed according to the furnace and tank number, and the mechanical properties must be verified according to the batch number. The verified qualified materials should have material markings.
5.1.4 All parts welded to the main body of the vehicle cylinder must be made of materials that are compatible with the weldability of the main material. 5.1.5 The welding materials used should ensure that the tensile strength of the welded weld shall not be lower than the lower limit of the specified value of the tensile strength of the parent material. 5.1.6 All parts and components in contact with liquefied petroleum gas should be compatible with liquefied petroleum gas and shall not react chemically with the liquefied petroleum gas contained.
5.2 Mechanical properties
5.2.1 The yield point of the main material of the vehicle cylinder shall not be greater than 0.8 times its tensile strength b. 5.2.2 The elongation 8 of the main material of the vehicle cylinder shall not be less than 20%. 6 Design
General provisions
6.1.1 Newly designed automotive cylinders shall be subjected to safety performance tests in accordance with Appendix A (Standard Appendix) to assess the rationality of the design. 6.1.2 The body of an automotive cylinder shall not consist of more than three parts, i.e., there shall be no more than one longitudinal weld and no more than two butt circumferential welds. 6.1.3 The shape of the automotive cylinder head shall be elliptical [see Figure 1a)], dish-shaped [see Figure 1b)] or hemispherical, and the straight edge height h of the head shall not be less than 25 mm.
6.2 Calculation of cylinder wall thickness
6.2.1 The simplified design wall thickness S shall be calculated according to formula (1) and rounded upward to retain one decimal place. PhD
20.4 _ Pr
Wherein, the weld coefficient value is specified as follows:
=1.0, 100% radiographic inspection of each butt weld; $=0.9, radiographic inspection of each butt weld for a length greater than or equal to 20%. 6.2.2 The design wall thickness S of the head is calculated according to formula (2) and rounded up to one decimal place. S,
Wherein, the shape coefficient K value of the head is specified as follows: PD,K
R0. 1D
（1）
（2）
K=1, standard elliptical head (H;=0.25D); the K value of other heads can be found in Figure 2.
GB17259--1998
a. It is the minimum value of yield stress specified in the selected material standard (MPa). 1.5A
0. 25 (H, /D,)
Applicable to the ratio H/D between 0.20 and 0.25a)
Applicable to the ratio H./D between 0.25 and 0.50b)
6.2.3 The design wall thickness S of the bottle body shall be the maximum value of S1 and S. and shall comply with the following provisions:a) When D<250mm, it shall not be less than 2mm;
0. 50 (H, / D,)
GB17259—1998
b) When D≥250mm, it shall not be less than the thickness S=250 calculated by formula (3)
·（3）
6.2.4 The nominal wall thickness S of the cylinder and the head shall be equal. When determining the nominal thickness of the bottle body, the negative deviation of the steel plate thickness and the process thinning amount shall be considered.
6.3 Opening holes
6.3.1 It is allowed to open holes on the head or cylinder. The openings should avoid stress concentration and weld areas. The distance between the edge of the hole and the edge of the butt weld should be no less than 25mm.
6.3.2 The openings should be reinforced with equal areas. The reinforcement method and calculation refer to Chapter 8 of GB150-1998, or reinforced by finite element analysis. The reinforcement material should be compatible with the welding performance of the bottle body material. 6.3.3 The diameter of the hole on the head cannot exceed 50% of the outer diameter of the bottle body. The distance between the edge of the hole and the outer circumference of the head measured in the vertical direction along the axis of the head should not be less than 10% of the outer diameter of the bottle body. 6.3.4 The welding of all openings and connectors on the bottle body should ensure full welds, and the protruding parts after welding, including valve seats and pipe joints, should not be greater than 35mm from the outer surface of the bottle body.
6.4 Welded joints
a) The welded joints of the main welds shall adopt the full penetration butt joint form; b) The longitudinal welds shall not have permanent pads;
c) The circumferential welds may use permanent pads, or integral pads with stepped shapes on one side of the joints; d) For other welding types, refer to Appendix J of GB150-1998. 6.5 Combination parts
6.5.1 The vehicle cylinders filled by the volumetric method shall be equipped with the following combination parts, and shall be inspected for any leakage after overall assembly. The combination parts should be designed as a whole, or they can be used separately. a) Filling check valve (including limited filling device); b) Liquid level gauge;
c) Safety valve;
d) Liquid outlet valve (including shut-off device).
6.5.2 The vehicle cylinders filled by the weighing method are allowed not to be equipped with a liquid level gauge. 6.5.3 The combined components shall comply with the corresponding component standards. The imported components shall comply with the corresponding foreign standards and meet the following requirements at the same time: a) The safety valve must be installed in the gas phase of the container. Its opening pressure shall be 2.50 ± 0.2 MPa and the return pressure shall not be less than 2.2 MPa. The discharge capacity of the safety valve shall not be less than the calculated value of formula (4) (when the pressure of the safety valve is 20% higher than the nominal working pressure): Q ≥ 10. 66 A0. 82
Where: Q-discharge capacity, m\/min;
A——container surface area (referring to the shell), m2. b) The filling limit valve shall ensure that the liquid inlet is automatically stopped when the liquid level in the bottle reaches the rated height, that is, 80% of the water volume of the steel bottle, and shall not be overfilled.
c) The liquid outlet valve shall automatically close and cut off the liquid outlet when the liquid outlet flow exceeds the specified value or the pipeline is broken. d) Liquid level gauge, with firm structure and convenient observation, must be sensitive and accurate in liquid level measurement. There should be a red mark of the highest safe liquid level on the dial, and the protruding part of the bottle body should be equipped with a protective device. 6.5.4 All interface threads should comply with the provisions of GB8335. 6.6 Accessories
6.6.1 The structural shape and layout of the accessories should facilitate the operation of the gas cylinder and the inspection of the welds. The connecting welds between the accessories and the bottle body should avoid the longitudinal and circumferential welds of the bottle body. The structural shape of the accessories and their connection with the bottle body should prevent the accumulation of liquid. 6.6.2 The nozzles and valves equipped on the bottle body should be equipped with protective devices, and ensure that these devices cannot be removed without cutting tools or other special tools. It should be ensured that the valves or nozzles and other connecting parts do not protrude outside the protective devices. 6.6.3 The steel stamped mark plate should be a permanent mark, and the connection with the bottle body should ensure that it cannot be removed without cutting tools or other special tools. 6.6.4 When the vehicle cylinder is installed in a closed vehicle box or luggage compartment, it should be equipped with a protective box, i.e., an accessory that seals the valve and other components, to ensure that the combined components on the cylinder body are contained, to collect any gas that may leak, and to have an exhaust port to discharge the collected leaked gas into the atmosphere outside the vehicle.
6.6.5 All accessories should ensure that they have the strength required for use, and all those connected to the cylinder body by welding must be completed before heat treatment. 7 Manufacturing and processing
7.1 Welding process assessment
7.1.1 Before producing vehicle cylinders, or when the cylinder body material, welding material, welding process, and welding equipment need to be changed during production, the manufacturing unit should conduct welding process assessment in accordance with JB4708. 7.1.2 Welding process assessment can be conducted on the welding assessment test plate or directly on the cylinder body. The welds for process assessment should represent the main welds (longitudinal welds, girth welds, and fillet welds) of vehicle cylinders. 7.1.3 The welding procedure qualification test plate shall be visually inspected, and the longitudinal and circumferential welds shall be 100% radiographically inspected. The inspection results shall comply with the provisions of 7.3 and 7.4.
7.1.4 The welded joints shall be subjected to tensile and bending tests. 7.1.5 The fillet welds at the openings of the bottle body shall be subjected to surface flaw detection, and the fillet weld specimens shall be cut according to JB4708 and subjected to macroscopic acid etching inspection according to GB226.
7.1.6 The requirements for the welding procedure qualification test results are as follows: a) The tensile strength of the welded joint shall comply with 7.14.5; b) The surface flaw detection shall comply with 7.4.4;
c) In the macroscopic acid etching inspection of the fillet weld, the weld shall be completely fused with the parent material, and there shall be no defects such as cracks, slag inclusions, dense pores and unfused welds;
d) There shall be no cracks when the bending specimen is bent to 100°, and the early cracking of the specimen edge can be ignored. 7.1.7 The welding process qualification document shall be approved by the chief technical officer of the vehicle cylinder manufacturing unit and stored in the technical file. 7.2 General provisions for welding www.bzxz.net
7.2.1 The welder who welds the vehicle cylinder shall pass the examination according to the "Test Rules for Boiler Pressure Vessel Welders" issued by the Ministry of Labor and hold a valid certificate. After welding, the welder shall stamp the welder's stamp at the appropriate position near the weld and have a traceable record. When there are special requirements in the drawings, they shall be in accordance with the drawing regulations.
7.2.2 The welding of the main weld of the vehicle cylinder shall adopt the automatic welding method and strictly follow the qualified welding process. 7.2.3 The shape and size of the welding groove shall comply with the drawing regulations. The groove surface shall be clean and smooth, and shall not have defects such as cracks, delamination and inclusions. 7.2.4 Welding (including weld repair) shall be carried out indoors, and the relative humidity in the room shall not be greater than 90%, otherwise measures shall be taken. When the temperature of the weld is below 0, the area where welding starts should be preheated. 7.2.5 Do not strike an arc at a non-welding location during welding. The longitudinal weld should have an arc-starting plate and an arc-extinguishing plate. The arc-starting and arc-extinguishing plates should be removed by cutting. The removed area should be ground flat. It is strictly forbidden to use the knocking method. 7.3 Appearance of the weld
7.3.1 The excess height of the bottle body butt weld is 0~3.5mm, and the difference between the widest and narrowest dimensions of the same weld is not greater than 4mm. 7.3.2 The weld leg of the fillet weld should smoothly transition to the surface of the parent material, and the weld leg height should not be less than the wall thickness of the bottle body. 7.3.3 The weld on the bottle body is not allowed to undercut, and there should be no cracks, pores, arc pits, four depressions and irregular mutations on the surface of the weld and the heat-affected zone. The spatter on both sides of the weld must be cleaned up. 7.4 Radiographic inspection and penetrant flaw detection of welds
7.4.1 Personnel engaged in radiographic inspection and penetrant flaw detection of welds of automotive cylinders must pass the examination and hold a valid certificate in accordance with the "Qualification Assessment Rules for Boiler and Pressure Vessel Nondestructive Testing Personnel" issued by the Ministry of Labor. 164
GB17259-1998
7.4.2 Radiographic inspection of welds shall be carried out in accordance with 9.2 and JB4730. The quality of radiographic film shall be AB grade, and the weld defect level shall not be lower than level I for welds and level III for girth welds. 7.4.3 The quality of butt welds of cylinders that have not been radiographically inspected shall also meet the requirements of 7.4.2. 7.4.4 The fillet welds at the openings on the body of automotive cylinders shall be subjected to 100% surface flaw detection, and no cracks or delamination shall be allowed. If cracks or delamination are found, records should be kept at all times, repairs or re-welding should be carried out, and the part should be re-inspected according to the original flaw detection method. 7.5 Weld repair
7.5.1 Weld repair shall be carried out according to the repair process. The repaired part shall be re-tested for appearance, radiographic inspection and surface flaw detection according to 7.3 and 7.4.
7.5.2 The number of repairs of the same part of the weld is only allowed to be times. 7.5.3 The repaired part shall be recorded in the product production inspection record and indicated in the product certificate. 7.6 Simplified body
7.6.1 When the simplified body is made of steel plate coil welding, the rolling direction of the steel plate shall be consistent with the circumferential direction of the simplified body. 7.6.2, the simplified body shall meet the following requirements after welding: a) The difference between the maximum and minimum diameters of the same cross section of the simplified body shall not exceed 0.01D, b) The misalignment 6 of the longitudinal weld of the simplified body shall not exceed 0.1Sn, see Figure 3; c) The angular height E of the longitudinal weld of the simplified body shall not exceed 0.1S, + 2mm, see Figure 4, measured with a sample with a length of 1/2D. Sample
7.7 Head
7.7.1 The head shall be made of a whole piece of steel plate
7.7.2 The shape tolerance and size tolerance of the head shall not exceed the provisions of Table 2. The symbols are shown in Figure 5. Table 2
Inner diameter of cylinder
400~500
Circumference tolerance
Maximum small diameter difference
Wheat surface
Gap between curved surface and sample
Inner height tolerance
GB17259
9-1998
7.7.3 The measured value of the minimum wall thickness of the head shall not be less than the designed wall thickness of the head. 0.8D
7.7.4 The longitudinal wrinkle depth of the straight edge of the head shall not be greater than 0.25%D and shall not be greater than 1.5mm. 7.8 Limit deviation of dimensions without tolerances
The limit deviation of dimensions without tolerances shall be in accordance with the provisions of GB/T1804, with the following specific requirements: a) Machined parts shall be GB/T1804-m;
b) Non-machined parts shall be GB/T1804-c; c) Length dimensions shall be GB/T1804-v.
7.9 Assembly
7.9.1 The pressure-bearing components of vehicle cylinders shall be visually inspected before assembly. Those that fail to meet the requirements shall not be assembled and shall not be assembled by force. 7.9.2 The misalignment b of the butt weld shall not be greater than 0.25Sn, the angular height E shall not be greater than 0.1S.+2mm, and the length of the inspection ruler shall not be less than 1/2D.
7.9.3 When the bottle body is composed of two parts, the straightness of the cylindrical barrel part shall not be greater than 0.2/1000. 7.9.4 The assembly of accessories and combination parts with the bottle body shall comply with the product drawings, the combination parts shall comply with 6.5, and the accessories shall comply with the requirements of 6.6. 7.9.5 When users (installers) assemble Class B cylinders for vehicles, they shall comply with the requirements of this standard. 7.10 Surface quality
The outer surface of the bottle body shall be smooth, and there shall be no cracks, heavy skin, inclusions, pits with a depth exceeding 0.5mm, scratches, corrosion and other defects, otherwise it shall be ground. The ground area shall be smooth, and its remaining wall thickness shall not be less than the designed wall thickness, and no oxide scale is allowed on the inner surface. 7.11 Heat treatment
7.11.1 After all welding is completed and the bottle body is inspected and qualified, the overall stress relief heat treatment must be carried out. Local heat treatment is not allowed, and heat treatment in an induction heating furnace should not be used. 7.11.2 When the bottle body is heat treated, there must be a qualified heat treatment process and it must be strictly implemented. 7.11.3 The heat treatment results shall be recorded in the product quality certificate. 7.12 Volume and weight
7.12.1 The measured water volume of vehicle cylinders shall not be less than its nominal volume. For vehicle cylinders with a nominal volume greater than 150L, the measured volume may be replaced by the theoretical volume, but there shall be no negative deviation. The unit of volume is liter (L). 7.12.2 After the vehicle cylinders are manufactured, the weight shall be measured one by one. The unit of weight is dry gram (kg). 7.12.3 The weight shall be measured using a scale with a range of 1.5 to 3.0 times the theoretical weight. Its accuracy shall meet the requirements of the minimum weighing error, and its verification cycle shall not exceed 3 months.
7.13 Pressure test and airtightness test
7.13.1 The pressure test shall be carried out after the overall heat treatment of the cylinder body. 7.13.2 The pressure test pressure is 3.3MPa, and the pressure gauge is not allowed to drop under this pressure. After maintaining the pressure for not less than 3 minutes, the bottle body 166
shall not have macroscopic deformation or leakage.
GB 172591998
7.13.3 After the pressure test, the inner surface of the cylinder shall be cleaned and dried. The air tightness test of the cylinder must be carried out after the pressure test is qualified. 7.13.4#
The air tightness test pressure is 2.2MPa. The pressure is maintained at the test pressure for not less than 1 minute. The tested bottle body shall not leak. If leakage is found on the weld during the pressure test and air tightness test, it can be repaired according to the provisions of 7.5. After the weld of the cylinder is repaired by 7.13.6
, the overall heat treatment shall be re-performed. If the weld is repaired due to pinhole leakage, it is not necessary to re-heat treat. 7. 13. 7
7.13.8 After the weld is repaired, the pressure resistance test and air tightness test shall be carried out again in accordance with the provisions of 7.13.2 and 7.13.5. 7.14 Mechanical properties test
7.14.1 For automotive steel cylinders with a nominal volume not exceeding 150L, sample bottles shall be drawn from the batch for mechanical properties test. The sample bottles must pass the radiographic inspection and the inspection one by one.
For automotive steel cylinders with a nominal volume greater than 150L, product welding test plates can be prepared in batches for mechanical properties test. 7.14.2 When the mechanical properties test is carried out on the bottle body, for a bottle body composed of two parts, the test sampling position shall be in accordance with Figure 6; for a cylinder composed of three parts, the test sample sampling position shall be in accordance with Figure 7. A-direction
1 tensile specimen
1 transverse face bend specimen
1 tensile specimen
1 transverse back bend specimen
1 tensile specimen
1 transverse face bend specimen
1 transverse back bend specimen
1 tensile specimen
1 transverse face bend specimen
1 transverse back bend specimen
1 tensile specimen
1 pressure specimen
|1 tensile specimen
Note: "×" in Figures 6 and 7 indicates the position of the weld. 7.14.3 When using product welded test plates for mechanical property test, the product welded test plates shall be loaded and unloaded on the same steel plate (or the same batch of steel plates in the same furnace) as the cylinder under test, and welded together with the longitudinal weld as the extended part of the longitudinal weld of the cylinder under test and heat treated in the same furnace as the cylinder under test. The test plate shall be stamped with the cylinder number and welder code of the cylinder under test. The welds on the test plates shall be visually inspected and 100% radiographically inspected and shall comply with the provisions of 7.3 and 7.4. The sampling positions on the welded test plates shall be in accordance with Figure 8. f.
CCCCCCC
1- tensile test specimen, 2~ bending test specimen, and the rest are shearing parts Figure 8
7.14.4 The weld section of the test specimen shall be good, and shall not have defects such as cracks, lack of fusion, lack of penetration, slag and pores. 7.14.5 Mechanical test results shall comply with the following provisions: a) The measured tensile strength b of the bottle body base material shall not be less than the lower limit of the value specified in the base material standard, and the elongation % shall not be less than 20%. b) Regardless of the position of the fracture of the welded joint specimen, the measured tensile strength shall not be less than the lower limit of the value specified in the base material standard.
c) There is no crack when the welded joint specimen is bent to 100°, and the early cracking of the specimen edge can be ignored. 7.15 Burst test
For automotive cylinders with a nominal volume not exceeding 150L, sample bottles shall be taken from the batch for burst test, and the burst test results shall comply with the following provisions:
a) The measured value of the burst pressure b shall not be less than the result calculated according to formula (5). b) The volume deformation rate when the bottle body breaks;
When ≤490MPa, ≥15%
When >490MPa, ≥12%.
P, - D. s.
2Sh x
（5）
c) The bottle body shall not produce fragments when it breaks, and the bursting hole shall not occur in the head (except for steel cylinders with only one girth weld and L≤2D), longitudinal weld and its fusion line, girth weld (except perpendicular to the girth weld) and fillet weld. d) The bursting hole of the bottle body is a plastic fracture, that is, there is an obvious shear lip on the fracture, but there is no obvious metal defect. 7.16 Coating
7.16.1 After the bottle body is inspected and qualified, the surface oil, rust, oxide scale, welding spatter shall be cleaned and coated while keeping it dry. 7.16.2 Putty is not allowed on the surface of the bottle body. 7.16.3 The outer surface color of the bottle body is silver-gray and shall comply with the provisions of GB7144. 8 Test methods
8.1 Material verification test
Verification test of chemical composition and mechanical properties of vehicle cylinder materials. Samples are taken for analysis and testing according to the methods specified in the material standards. 8.2 Mechanical properties test of welding process qualification test plate 168
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