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5.1, 5.2, 5.4, 5.6, 6.4, 6.8.2, Annex A and Annex B are voluntary and the rest are compulsory.
This standard replaces GB 18248-2000 Seamless steel tubes for gas cylinder, with respect to which, the following main technical changes have been made:
——standard scope is modified;
——the dimension tolerances of steel tubes are modified;
——the requirements for P and S contents of steel are adjusted, and 34CrMo4 and 30CrMnSiA are added in steel grades;
——the smelting method of steel is modified;
——the manufacturing method of tube by hot expanding is added, and the delivery state of steel tubes is modified;
——the macroscopic inspection is deleted;
——for steel tubes made of rolled (forged) tube blanks, the inspection position of nonmetallic inclusion is changed from on the tube blank to on the steel tube, and the nonmetallic inclusion inspection requirements for steel tubes are modified according to GB/T 10561;
——the quality requirements for straight ways on inner and outer surfaces of steel tubes are added;
——the longitudinal mechanical property data measured on the test pieces from the steel tube made of heat-treated steel blank are modified, and the required values are changed to the reference values, which are listed in Annex B.
Annexes A and B are informative.
This standard was proposed by China Iron and Steel Industry Association.
This standard is under the jurisdiction of National Technical Committee on Iron and Steel of Standardization Administration of China.
The previous edition of this standard is as follows:
——GB 18248-2000.
Seamless steel tubes for gas cylinder
1 Scope
This standard specifies the dimension, shape, weight, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of seamless steel tubes for gas cylinder and accumulator shell.
This standard is applicable to the manufacturing of seamless steel tubes for gas cylinder and accumulator shell.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding corrections) to, or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition applies.
GB/T 222 Permissible tolerances for chemical composition of steel products
GB/T 223.5 Steel and iron - Determination of acid-soluble silicon and total silicon content - Reduced molybdosilicate spectrophotometric method
GB/T 223.11 Iron, steel and alloy - Determination of chromium content - Visual titration or potentiometric titration 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-benzoy-N-phenylhydroxylamine extraction photometric method for the determination of vanadium content
GB/T 223.17 Methods for chemical analysis of iron, steel and alloy - The diantipyrylmethane 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 223.24 Methods for chemical analysis of iron, steel and alloy - The extraction separation - The dimethylglyoxime spectrophotometric method for the determination of nickel content
GB/T 223.26 Iron, steel and alloy - Determination of molybdenum content - The thiocyanate spectrophotometric method
GB/T 223.30 Methods for chemical analysis of iron, steel and alloy - The arsenazo III spectrophotometric method for the determination of zirconium content after separation by p-bromomandelic acid
GB/T 223.40 Iron, steel and alloy - Determination of niobium content by the sulphochlorophenol S spectrophotometric method
GB/T 223.53 Methods for chemical analysis of iron, steel and alloy - The flame atomic absorption spectrophotometric method for the determination of copper content
GB/T 223.54 Methods for chemical analysis of iron, steel and alloy - The flame atomic absorption spectrophotometric method for the determination of nickel 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 223.62 Methods for chemical analysis of iron, steel and alloy - The butyl acetate extraction photometric method for the determination of phosphorus 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 223.64 Iron, steel and alloy - Determination of manganese content - Flame atomic absorption spectrometric method
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 223.76 Methods for chemical analysis of iron, steel and alloy - The flame atomic absorption spectrometric method for the determination of vanadium content
GB/T 223.78 Methods for chemical analysis of iron, steel and alloy - Curcumin spectrophotometric method for the determination of boron content
GB/T 228-2002 Metallic materials - Tensile testing at ambient temperature (eqv ISO 6892:1998)
GB/T 229-1994 Metallic materials - Charpy notch impact test (eqv ISO 148:1983 & ISO 83:1976)
GB/T 241-2007 Metal materials - Tube - Hydrostatic pressure test
GB/T 2102-2006 Acceptance, packing, marking and quality certification of steel pipe
GB/T 2975-1998 Steel and steel products - Location and preparation of test pieces for mechanical testing (eqv ISO 377:1997)
GB/T 4336-2002 Standard test method for spark discharge atomic emission spectrometric analysis of carbon and low-alloy steel (routine method)
GB/T 5777-1996 Seamless steel pipe and tubing - Methods for ultrasonic testing (eqv ISO 9303:1989)
GB/T 7735-2004 Steel tubes - The inspection method on eddy current test (ISO 9304:1989, MOD)
GB/T 10561-2005 Steel - Determination of content of nonmetallic inclusions - Micrographic method using standards diagrams (ISO 4967:1998, IDT)
GB/T 12606-1999 Steel tubes - The testing method of magnetic flux leakage (eqv ISO 9402:1989, ISO 9598:1989)
GB/T 17395 Dimensions, shapes, masses and tolerances of seamless steel tubes (GB/T 17395-2008, ISO 1127:1992, ISO 4200:1991, ISO 5252:1991, NEQ)
GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition (GB/T 20066-2006, ISO 14284:1996, IDT)
GB/T 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method) (GB/T 20123-2006, ISO 15350:2000, IDT)
GB/T 20125 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method
GB/T 20126 Unalloyed steel - Determination of low carbon content - Part 2: Infrared absorption method after combustion in an induction furnace (with preheating) (GB/T 20126-2006, ISO 15349-2:1999, IDT)
3 Codes
For the purposes of this standard, the following codes apply:
——D: nominal outside diameter;
——Smin: minimum wall thickness;
——S: nominal wall thickness.
4 Ordering information
The contract or order for ordering steel tubes according to this standard shall include but not be limited to the following contents:
a) No. of this standard;
b) product name;
c) steel grade;
d) manufacturing method and delivery state of steel tube;
e) the order quantity (total weight or total length);
f) dimensions and specifications;
g) special requirements.
5 Dimension, shape, weight and tolerance
5.1 Outside diameter and wall thickness
5.1.1 Unless otherwise specified in the contract, steel tubes shall be delivered according to the nominal outside diameter (D) and nominal wall thickness (S). As required by the purchaser, steel tubes may be delivered according to the nominal outside diameter and minimum wall thickness (Smin) upon agreement between the supplier and the purchaser.
5.1.2 The outside diameter and wall thickness of steel tubes shall meet the requirements of GB/T 17395. As required by the purchaser, steel tubes other than those specified in GB/T 17395 may be supplied upon agreement between the supplier and the purchaser.
5.1.3 The tolerances of nominal outside diameter and nominal wall thickness of steel tubes shall meet those specified in Table 1. The nominal outside diameter and minimum wall thickness, if adopted, shall have tolerances meeting those specified in Table 2.
5.1.4 Unless otherwise specified in the contract, the tolerance of wall thickness of steel tube delivered shall be in ordinary-grade precision. As required by the purchaser and through the negotiation between the supplier and the purchaser, the tolerance of wall thickness of steel tube delivered may be in high-grade precision.
Foreword i
1 Scope
2 Normative references
3 Codes
4 Ordering information
5 Dimension, shape, weight and tolerance
6 Technical requirements
7 Inspection and test methods
8 Inspection rules
9 Packaging, marking and quality certificate
Annex A (Informative) Comparison between steel grades in this standard and those in foreign standards
Annex B (Informative) Reference values of mechanical property data
Bibliography