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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces and combines GB/T 11253-2007 Cold-rolled sheets and strips of carbon structural steels and GB/T 716-1991 Cold-rolled carbon structural steel strips, with respect to which, the following main technical changes have been made:
——the thickness range of steel sheets and strips and the width range of cold-rolled narrow steel sheets and strips are modified (see Clause 1; Clause 1 of GB/T 11253-2007);
——the classification and code of surface structure are modified (see 3.2; 3.2 of GB/T 11253-2007);
——the order contents are modified by adding surface structure types and oiling requirements (see Clause 4; Clause 4 of GB/T 11253-2007);
——the dimension, shape, weight and tolerance of cold-rolled narrow steel sheets and strips and are modified (see Table 1; Table 1 of GB/T 716-1991);
——Grade Q325 and corresponding chemical composition, mechanical properties and processing properties are added (see Tables 2, 3 and 4);
——technical requirements for cold-rolled narrow steel sheets and strips are modified (see Table 3; Table 3 of GB/T 716-1991);
——the requirements for surface structure are added (see Table 6);
——the rounding-off requirements for numerical values are added (see 8.4);
——the requirements for types of quality certificates of steel sheets and strips are deleted (see Clause 9 of GB/T 11253-2007).
This standard was proposed by China Iron and Steel Industry Association.
This standard is under 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 11253-1989 and GB/T 11253-2007;
——GB/T 716-1983 and GB/T 716-1991.
Cold-rolled sheet and strip of carbon structural steels
1 Scope
This standard specifies the order contents, dimension, shape and weight, technical requirements, test methods, inspection rules, as well as packaging, marking and quality certificate of cold-rolled steel sheets and strips of carbon structural steels.
This standard is applicable to cold-rolled thin sheets and strips of carbon structural steels with a thickness of not greater than 4mm, including cold-rolled wide strips, sheared sheets and slit wide strips with a width of not less than 600mm (hereinafter referred to as wide steel sheets and strips) as well as cold-rolled narrow strips and sheared sheets with a width of 250~<600mm (hereinafter referred to as narrow steel sheets and strips). It may serve as a reference for the single cold-rolled steel sheet with a width of not less than 600mm.
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 223.3 Methods for chemical analysis of iron, steel and alloy - The diantipyryl methane phosphomolybdate gravimetric method for the determination of phosphorus content
GB/T 223.9 Iron, steel and alloy - Determination of aluminium content - Chrome azurol S photometric method
GB/T 223.11 Iron, steel and alloy - Determination of chromium content - Visual titration or potentiometric titration method
GB/T 223.18 Methods for chemical analysis of iron, steel and alloy - The sodium thiosulfate separation iodimetric method for the determination of copper 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 223.37 Methods for chemical analysis of iron, steel and alloy - The indophenol blue photometric method for the determination of nitrogen content after distillation separation
GB/T 223.58 Methods for chemical analysis of iron, steel and alloy - The sodium arsenite-sodium nitrite titrimetric method for the determination of manganese 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 223.64 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 223.71 Methods for chemical analysis of iron, steel and alloy - The gravimetric method after combustion in the pipe furnace for the determination of carbon content
GB/T 223.72 Iron, steel and alloy - Determination of sulfur content - Gravimetric method
GB/T 228.1-2010 Metallic materials - Tensile testing - Part 1: Method of test at room temperature
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 strip and sheet
GB/T 2523 Measuring method of surface roughness and peak count for cold-rolled metal sheet (strip)
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing
GB/T 4336 Carbon and low-alloy steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (routine method)
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 15391 Dimension, shape and tolerances for cold-rolled steel strips with a width less than 600mm
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 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method)
GB/T 20125 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method
3 Classification and code
3.1 According to the surface quality, steel sheets and strips are classified into:
——relatively high grade surface FB;
——high grade surface FC.
3.2 According to the surface structure, steel sheets and strips are classified into:
——ultra-smooth surface b;
——shiny surface B;
——pitted surface D.
Note: ultra-smooth surface is only applicable to narrow strip and its sheared sheets.
4 Order contents
4.1 Contracts or orders made based on this standard shall cover the following contents:
a) product name (wide or narrow sheet or strip);
b) No. of this standard;
c) grade;
d) dimension and precision;
e) surface quality grade;
f) surface structure;
g) oiling;
h) edge condition (trimmed EC or untrimmed EM);
i) packaging method;
j) weight;
k) use;
l) special requirements.
4.2 If information, e.g., dimension and unevenness precision, surface quality grade, surface structure type, edge condition and packaging method, is not specified in the order contract, the oiled and trimmed sheet or strip with common dimension and unevenness precision, relatively high grade surface quality and pitted surface structure under this standard shall be supplied, and packaged according to the method provided by the supplier.
5 Dimension, shape and weight
5.1 The dimension, shape, weight and tolerance of wide steel sheets and strips shall meet those specified in GB/T 708.
5.2 The dimension, shape, weight and tolerance of narrow steel sheets and strips shall meet those specified in GB/T 15391, wherein, the width tolerance shall meet those specified in Table 1.
Foreword i
1 Scope
2 Normative references
3 Classification and code
4 Order contents
5 Dimension, shape and weight
6 Technical requirements
7 Test methods
8 Inspection rules
9 Packaging, marking and quality certificate
