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This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 3639-2009 Seamless cold-drawn or cold-rolled steel tubes for precision applications. In addition to structural adjustment and editorial changes, the following main technical changes have been made with respect to GB/T 3639-2009:
a) the normative references are changed (see Clause 2; Clause 2 of Edition 2009);
b) the manufacturing method in the order content is deleted (see Clause 4 of Edition 2009);
c) the dimensional specifications are changed (see Table 1; Table 1 in Edition 2009);
d) the normal length ranges are changed (see 6.2.1; 5.2.1 of Edition 2009);
e) the flexibility requirement per meter is changed (see 6.3.1; 5.3.1 of Edition 2009);
f) the requirement for inhomogeneity of wall thickness is changed (see 6.5; 5.5.2 of Edition 2009);
g) the requirement for permissible deviations of weight is deleted (see 5.6 of Edition 2009);
h) the steel grade Q345B is changed to Q355B, and the steel grades 25Mn, Q420B, 25CrMo and 42CrMo and their chemical composition and mechanical property requirements are added (see 7.1.1 and 7.4; 6.1.1 and 6.4 of Edition 2009);
i) the smelting method for steel is changed (see 7.2.1; 6.2.1 of Edition 2009);
j) The inspection requirements for compactness are changed (see 7.6; 6.6 of Edition 2009);
k) the requirement for surface roughness is changed (see 7.7; 6.7 of Edition 2009);
l) the requirement of nondestructive testing is added (see 7.9);
m) the requirement for surface rust prevention is increased (see 10.1);
n) Annexes A, B, C and D are deleted (see Annexes A, B, C and D of Edition 2009).
Attention is drawn to the possibility that some of the elements of this standard may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by China Iron and Steel Industry Association.
This document is under the jurisdiction of SAC/TC 183 National Technical Committee on Iron and Steel of Standardization Administration of China.
This document was first issued in 1983, revised for the first time in 2000, and for the second time in 2009. This is the third revision.
Seamless cold-drawn or cold-rolled steel tubes for precision applications
1 Scope
This document specifies the classification, designation, order content, dimensions, shape, weight and permissible deviation, technical requirements, test methods, inspection rules, packaging, marking and quality certificates for seamless cold-drawn or cold-rolled steel tubes for precision applications.
This document is applicable to manufacturing seamless cold-drawn or cold-rolled steel tubes for precision applications (hereinafter referred to as steel pipes) with special dimensional accuracy and high surface quality requirements for mechanical structures, hydraulic equipment and automobile parts.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. 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 223.5 Steel and iron - Determination of acid-soluble silicon and total silicon content - Reduced molybdosilicate spectrophotometric method
GB/T 223.9 Iron, steel and alloy - Determination of aluminum content - Chrome azurol S photometric method
GB/T 223.12 Methodsfor chemical analysis of iron, steel and alloy - The sodium carbonate separation-diphenyl carbazide photometric method for the determination of chromium 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 223.37 Iron, steel and alloy - Determination of nitrogen content - Indophenol blue spectrophotometric method after distillation separation
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/T223.59 Iron,steel and alloy - Determination of phosphorus content - Bismuth phosphomolybdate blue spectrophotometric method and antimony phosphomolybdate blue spectrophotometric method
GB/T 223.63 Methods for chemical analysis of iron，steel and alloy - The sodium (potassium) periodate photometric method for the determination of manganese contents
GB/T 223.85 Steel and iron - Determination of sulfur content - Infrared absorption method after combustion in an induction furnace
GB/T 223.86 Steel and iron - Determination of total carbon content - Infrared absorption method after combustion in an induction furnace
GB/T 228.1 Metallic materials - Tensile testing - Part 1: Method of test at room temperature
GB/T 242 Metal materials-Tube - Drift-expending test
GB/T 246 Metallic materials - Tube - Flattening test
GB/T 699 Quality carbon structure steels
GB/T 1031 Geometrical product specifications (GPS) - Surface texture: Profile method - Surface roughness parameters and their values
GB/T 1591 High strength low alloy structural steels
GB/T 2102 Acceptance, packing, marking and quality certification of steel pipe
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing
GB/T 3077 Alloy structure steels
GB/T 4336 Carbon and low-alloy steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (routine method)
GB/T 5777-2019 Automated full peripheral ultrasonic testing of seamless and welded (except submerged arc-welded) steel tubes for the detection of longitudinal and/or transverse imperfections
GB/T 7735-2016 Automated eddy current testing of seamless and welded (except submerged arc-welded) steel tubes for detection of imperfections
GB/T 12606-2016 Automated full peripheral flux leakage testing of seamless and welded (except submerged arc-welded) ferromagnetic steel tubes for the detection of longitudinal and/or transverse imperfections
GB/T 17395 Dimensions, shapes, masses and tolerances of seamless steel tubes
GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition
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 20124 Steel and iron - Determination of nitrogen content - Thermal conductimetric method after fusion in a current of inert gas (Routine method)
GB/T 20125 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method
GB/T 30062 Terminology of steel pipes and tubes
GB/T 40080 Nondestructive testing of steel tubes - Automated electromagnetic testing of seamless and welded (except submerged arc-welded) steel tubes for the verification of hydraulic leaktightness
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 30062 and the following apply.
4 Classification and designation
Classification and designation of steel pipes according to delivery states are as follows:
a) cold working/hard state: +C;
b) cold working/soft state:+LC;
c) stress relief annealing state: +SR;
d) annealing state: +A;
e) normalizing state: +N.
5 Order content
The contract or order under which steel pipes are ordered according to this document shall include the following content:
a) the number of this document;
b) the product name;
c) the grade(s) of steel;
d) the dimensional specifications;
e) the ordered quantity (total weight or total length);
f) the delivery states;
g) special requirements.
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6 Dimensions, shapes, weight and permissible deviations
6.1 Dimensions
6.1.1 Steel pipes are usually delivered according to nominal outer diameter (D) and nominal wall thickness (S). If required by the purchaser and agreed through negotiation between the supplier and the purchaser, the steel pipes may also be delivered according to nominal outer diameter and nominal inner diameter (d) or with nominal inner diameter and nominal wall thickness.
6.1.2 The dimensions of steel pipes shall be in accordance with those specified in Table 1.
6.1.3 For steel pipes delivered in cold working (+C, +LC) state, the permissible deviations of nominal outer diameter and nominal inner diameter shall be in accordance with those specified in Table 1. For steel pipes delivered after heat treatment (in +SR, +A, +N states), the permissible deviations of nominal outer diameter and nominal inner diameter shall be in accordance with those specified in Table 2.
Foreword II
1 Scope
2 Normative references
3 Terms and definitions
4 Classification and designation
5 Order content
6 Dimensions, shapes, weight and permissible deviations
7 Technical requirements
8 Inspection and test methods
9 Inspection rules
10 Packaging, marking and quality certificate
