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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 6653-2008 Steel plates and strips for welded gas cylinders. The following main technical changes have been made with respect to GB/T 6653-2008:
——The chemical composition requirements have been modified;
——The requirements for impact properties have been modified;
——The requirements for nonmetallic inclusions have been modified;
——The requirements for surface quality have been modified.
This standard was proposed by the China Iron and Steel Association.
This standard is under the jurisdiction of the SAC/TC 183 National Technical Committee on Iron and Steel of Standardization Administration of China.
The previous editions of this standard are as follows:
——GB 6653-1986, GB 6653-1994 and GB/T 6653-2008.
Steel plates and strips for welded gas cylinders
1 Scope
This standard specifies the dimensions, shapes, weights and permissible deviations, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of steel plates and strips for welded gas cylinders.
This standard is applicable to such hot-rolled steel plates and strips with a thickness falling within the range of 2.0 mm~14.0 mm and cold-rolled steel plate and strips with a thickness falling within the range of 1.5 mm~4.0 mm that used for welded gas cylinders.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 222 Permissible tolerances for chemical composition of steel products
GB/T 223.9 Iron, steel and alloy - Determination of aluminium content - Chrom azurol S photometric method
GB/T 223.12 Methods for chemical analysis of iron, steel and alloy - The sodium carbonate separation-diphenyl carbazide photometric method for the determination of chromium content
GB/T 223.14 Methods for chemical analysis of iron, steel and alloy - The n-benzoyl-n-phenylhydroxylamine extraction photometric method for the determination of vanadium content
GB/T 223.16 Methods for chemical analysis of iron, steel and alloy - The chromotropic acid photometric method for the determination of titanium content
GB/T 223.19 Methods for chemical analysis of iron steel and alloy - The neocuproine-chloroform extraction photometric method for the determination of copper content
GB/T 223.23 Iron, steel and alloy - Determination of nickel content - The dimethylglyoxime spectrophotometric method
GB/T 223.26 Iron, steel and alloy - Determination of molybdenum content - The thiocyanate spectrophotometric method
GB/T 223.40 Iron, steel and alloy - Determination of niobium content by the sulphochlorophenol S spectrophotometric method
GB/T 223.49 Methods for chemical analysis of iron, steel and alloy - Extraction separation-chlorophosphonazo mA spectrophotometric method for the determination of the total rare earth content
GB/T 223.59 Iron, steel and alloy - Determination of phosphorus content - Bismuth phosphomolybdate blue spectrophotometric method and antimony phosphomolybdate blue spectrophotometric method
GB/T 223.60 Methods for chemical analysis of iron, steel and alloy - The perchloric acid dehydration gravimetric method for the determination of silicon content
GB/T 223.63 Methods for chemical analysis of iron, steel and alloy - The sodium (potassium) periodate photometric method for the determination of manganese content
GB/T 223.68 Methods for chemical analysis of iron, steel and alloy - The potassium iodate titration method after combustion in the pipe furnace for the determination of sulfur content
GB/T 223.69 Iron, steel and alloy - Determination of carbon contents - Gas-volumetric method after combustion in the pipe furnace
GB/T 228.1 Metallic materials - Tensile testing - Part 1: Method of test at room temperature
GB/T 229 Metallic materials - Charpy pendulum impact test method
GB/T 232 Metallic materials - Bend test
GB/T 247 General rule of package, mark and certification for steel plates (sheets) and strips
GB/T 708 Dimension, shape, weight and tolerance for cold-rolled steel plates and sheets
GB/T 709 Dimension, shape, weight and tolerances for hot-rolled steel plates and sheets
GB/T 2975 Steel and steel products - Location and preparation of test pieces for mechanical testing
GB/T 4336 Standard test method for spark discharge atomic emission spectrometric analysis of carbon and low - Alloy steel (routine method)
GB/T 6394 Metal-methods for estimating the average grain size
GB/T 8170 Rules of rounding off for numerical values & expression and judgement of limiting values
GB/T 10561 Steel - Determination of content of nonmetallic inclusions - Micrographic method using standards diagrams
GB/T 14977 General requirement for surface condition of hot-rolled steel plates
GB/T 17505 Steel and steel products - General technical delivery requirements
GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition
GB/T 20125 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method
3 Steel grade expression methods
The steel grade consists of the acronym "HP" of "焊瓶" according to the Chinese phonetic alphabet and the lower limit value of lower yield strength.
Example: HP295, where:
HP——the acronym "HP" of "焊瓶" (welded gas cylinders) according to the Chinese phonetic alphabet;
295——the lower limit value of lower yield strength, MPa.
4 Order contents
Contracts or orders made based on this standard shall cover the following items:
a) Standard No.;
a) Product type (steel plate or strip);
c) Steel grade;
d) Delivery status;
e) Specifications and dimensional tolerances;
f) Weight;
g) Other requirements.
5 Dimensions, shapes, weights and permissible deviations
5.1 The dimension, shape, weight and permissible deviation of hot-rolled steel plates and strips shall meet those specified in GB/T 709.
5.2 The dimension, shape, weight and permissible deviation of cold-rolled steel plates and strips shall meet those specified in GB/T 708.
6 Technical requirements
6.1 Grades and chemical composition of steel
6.1.1 Steel grade and chemical composition (smelting analysis) shall meet the requirements of Table 1.
6.1.2 In order to improve the property of steel, one or more trace elements such as V, Nb, Ti and the like may be added to each steel grade, and the content thereof shall conform to the provisions in Table 1.
6.1.3 For HP235 and HP265 which are cold-rolled annealed steel plates, the upper limit of carbon content may be up to 0.20% and the upper limit of manganese content up to1.00% on condition that their properties are ensured.
6.1.4 For steel of all steel grades, the content of residual elements Cr, Ni and Mo shall be no more than 0.30% and the content of Cu shall be no more than 0.20%, which, if guaranteed by the Supplier, may not be subject to analysis.
6.1.5 In order to improve the internal quality of steel, appropriate amount of rare earth elements may be added to each grade of steel.
6.1.6 The permissible deviation of chemical composition of finished steel plates and strips shall meet the requirement of GB/T 222.
Table 1 Chemical composition
Steel grade Chemical compositiona,b (mass fraction)/%
C Si Mn P S Nb V Ti Nb+V Als
Not greater than Not less than
HP235 0.16 0.10c 0.80 0.025 0.012 0.05 0.10 0.06 0.12 0.015
HP265 0.18 0.10c 0.80 0.025 0.012 0.05 0.10 0.06 0.12 0.015
HP295 0.18 0.10c 1.00 0.025 0.012 0.05 0.10 0.06 0.12 0.015
HP325 0.20 0.35 1.50 0.025 0.012 0.05 0.10 0.06 0.12 0.015
HP345 0.20 0.35 1.50 0.025 0.012 0.05 0.10 0.06 0.12 0.015
a For HP265 and HP295, the manganese content shall be allowed to increase by 0.05% based on the specified maximum manganese content for every 0.01% reduction of carbon content relative to the specified maximum carbon content; for HP265, the maximum manganese content shall not be allowed to exceed 1.00%; for HP295, the maximum manganese content shall not be allowed to exceed 1.20%.
b The content of acid soluble aluminum (Als) may be determined by measuring the content of total aluminum (Alt), which shall not be less than 0.020%.
c For steel plates or strips with thickness not less than 6 mm, the Si content is allowed to be not more than 0.35%.
6.2 Smelting method
Steels shall be smelted by converter or electric furnace, and subject to external refining. Unless the Demander has special requirements, the smelting method shall be selected by the Supplier.
6.3 Delivery state
6.3.1 Hot-rolled steel plates and strips shall be delivered in hot rolled, controlled rolled or heat-treated state. Products may be delivered in hot-rolled pickled state based on the negotiation between the Supplier and the Demander, with such requirements specified in the contract.
Foreword i
1 Scope
2 Normative references
3 Steel grade expression methods
4 Order contents
5 Dimensions, shapes, weights and permissible deviations
6 Technical requirements
7 Test methods
8 Inspection rules
9 Packaging, marking and quality certificate
