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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 8162-2008 Seamless steel tubes for structural purposes, and the following main technical changes have been made with respect to GB/T 8162-2008:
——The tolerances for the outside diameter and wall thickness of cold drawn (rolled) seamless steel tubes are modified (see 4.2.1 and 4.2.3; 4.2.1 and 4.2.3 of Edition 2008);
——The random length range and the tolerance requirements for cut length of steel tubes are modified (see 4.3.1 and 4.3.3.2; 4.3.1 and 4.3.3.2 of Edition 2008);
——The grades Q235, Q275, Q295, 12CrMo, 15CrMo, 12CrMoV and 12Cr1MoV and related technical requirements are deleted (see 5.1.2, 5.1.3 and 5.4.1; 5.1.1 and 5.4.1 of Edition 2008);
——The grades, chemical composition and carbon equivalent table of high strength low alloy structural steels are added (see 5.1.2);
——The grades of Q500, Q550, Q620 and Q690 high strength low alloy structural steels and related technical requirements are added (see 5.1.2 and 5.4.1);
——The hot extrusion manufacturing method for steel tubes is deleted (see 5.2.3 of Edition 2008);
——The requirements for flattening test of Grade Q390 are added (see 5.5.1);
——The galvanized coating and related technical requirements are added (see 5.8 and Annex A).
This standard was proposed by the China Iron and Steel Association.
This standard is under the jurisdiction of the National Technical Committee on Iron and Steel of Standardization Administration of China (SAC/TC 183).
The previous editions of this standard are as follows:
——GB/T 8162-1987, GB/T 8162-1999 and GB/T 8162-2008.
Seamless steel tubes for structural purposes
1 Scope
This standard specifies the order contents, dimensions, shapes and weights, technical requirements, test methods, inspection rules, and packaging, marking and quality certificate of seamless steel tubes for structural purposes.
This standard is applicable to the seamless steel tubes for mechanical structure and general engineering structure purposes.
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 223.5 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 aluminium content - Chrom azurol S photometric 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-benzoyl-n-phenylhydroxylamine extraction photometric method for the determination of vanadium 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 223.37 Methods for chemical analysis of iron, steel and alloy - The indophenol blue photometric methods for the determination of nitrogen content after distillation separation
GB/T 223.40 Iron, steel and alloy - Determination of niobium content by the sulphochlorophenol S spectrophotometric method
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 223.68 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 223.78 Methods for chemical analysis of iron, steel and alloy - Curcumin spectrophotometric method for the determination of boron content
GB/T 223.84 Steel and alloy - Determination of titanium content - Diantipyrylmethane spectrophotometric method
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 229 Metallic materials - Charpy pendulum impact test method
GB/T 231.1 Metallic materials - Brinell hardness test - Part 1: Test method
GB/T 244 Metallic materials - Tube - Bend test
GB/T 246 Metallic materials - Tube - Flattening test
GB/T 699 Quality carbon structure 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 5777-2008 Seamless steel pipe and tubing methods for ultrasonic testing
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
YB/T 4149 Continuously cast round billet for seamless steel tube rolling
YB/T 5221 Alloy structure steel round tube blank hot rolled and forged for making seamless tube
YB/T 5222 Quality hot rolled and forged carbon structural steel round tube blank
3 Order contents
The contract or order for ordering steel tubes according to this standard shall include the following contents:
a) Standard No.;
b) Product name;
c) The steel grade, and the quality grade (if any);
d) Dimensions;
e) The order quantity (total weight or total length);
f) Delivery state;
g) Special requirements.
4 Dimensions, shapes and weights
4.1 Outside diameter and wall thickness
The nominal outside diameter (D) and nominal wall thickness (S) of steel tubes shall be in accordance with those specified in GB/T 17395. As required by the purchaser, steel tubes with other outside diameter and wall thickness may be supplied upon agreement between the supplier and purchaser.
4.2 Tolerances for outside diameter and wall thickness
4.2.1 The tolerances for outside diameter of steel tubes shall be in accordance with those specified in Table 1.
Table 1 Tolerances for outside diameter of steel tubes In: mm
Steel tube type Tolerance
Hot rolled (expanded) steel tube ±1%D or ±0.5, whichever is greater
Cold drawn (rolled) steel tube ±0.75%D or ±0.3, whichever is greater
4.2.2 The tolerances for wall thickness of hot rolled (expanded) steel tubes shall be in accordance with those specified in Table 2.
Table 2 Tolerances for wall thickness of hot rolled (expanded) steel tubes In: mm
Steel tube type Nominal outside diameter D of steel tube S/D Tolerance
Hot rolled steel tube ≤102 — ±12.5%S or ±0.4, whichever is greater
>102 ≤0.05 ±15%S or ±0.4, whichever is greater
>0.05~0.10 ±12.5%S or ±0.4, whichever is greater
>0.10 +12.5%S
-10%S
Hot expanded steel tube — ±15%S
4.2.3 The tolerances for wall thickness of cold drawn (rolled) steel tubes shall be in accordance with those specified in Table 3.
Table 3 Tolerances for wall thickness of cold drawn (rolled) steel tubes In: mm
Steel tube type Nominal wall thickness S of steel tube Tolerance
Cold drawn (rolled) steel tube ≤3 or ±0.15, whichever is greater
>3~10 +12.5%S
-10%S
>10 ±10%S
4.2.4 As required by the purchaser and indicated in the contract upon the agreement between the supplier and the purchaser, steel tubes beyond the dimensional tolerances specified in Tables 1, 2 and 3 may be supplied.
4.3 Length
4.3.1 Random length
The random length of steel tubes is 3,000mm~12,000mm. As required by the purchaser, steel tubes beyond the random length range may be supplied upon agreement between the supplier and purchaser.
4.3.2 Range length
As required by the purchaser and indicated in the contract upon the agreement between the supplier and the purchaser, steel tubes may be delivered in range length.
4.3.3 Cut length and multiple length
4.3.3.1 As required by the purchaser and indicated in the contract upon the agreement between the supplier and the purchaser, steel tubes may be delivered in cut length or multiple length.
4.3.3.2 Where the steel tubes are delivered in cut length or multiple length, their tolerances for length shall meet the following requirements:
a) When the cut length or multiple length is not greater than 6,000mm, the tolerances shall be mm;
b) When the cut length or multiple length is greater than 6,000mm, the tolerances shall be mm;
4.3.3.3 Where the steel tubes are delivered in multiple length, notch allowance shall be reserved for each multiple length according to following requirements:
a) When D≤159mm, the notch allowance shall be 5mm~10mm;
b) When D>159mm, the notch allowance shall be 10mm~15mm.
As agreed between the supplier and the purchaser, steel tubes with other notch allowances may be supplied.
Foreword II
1 Scope
2 Normative references
3 Order contents
4 Dimensions, shapes and weights
4.1 Outside diameter and wall thickness
4.2 Tolerances for outside diameter and wall thickness
4.3 Length
4.4 Curvature
4.5 Out-of-roundness and wall unevenness
4.6 End shape
4.7 Weight
5 Technical requirements
5.1 Grades and chemical composition of steel
5.2 Manufacturing method
5.3 Delivery state
5.4 Mechanical properties
5.5 Processing properties
5.6 Surface quality
5.7 Non-destructive testing
5.8 Galvanized coating
6 Test methods
7 Inspection rules
7.1 Inspection and acceptance
7.2 Batching rules
7.3 Sampling quantity
7.4 Reinspection and judgment rules
8 Packaging, marking and quality certificate
Annex A (Normative) Galvanized coating
