GB/T Translated English of Chinese Standard: GB/T NATIONAL STANDARD OF THE

Transcription

1 Translated English of Chinese Standard: GB/T GB NATIONAL STANDARD OF THE PEOPLE S REPUBLIC OF CHINA ICS H 46 GB/T Replacing GB/T Cold-rolled Sheets and Strips of Carbon Structural Steels 碳素结构钢冷轧薄钢板及钢带 (ISO 4997:1999 Cold-reduced carbon steel sheet of structural quality, NEQ) Issued on: October 25, 2007 Implemented on: April 01, 2008 Issued by: General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ); Standardization Administration (SAC) of the People's Republic of China. Page 1 of 12

2 Table of Contents 1 Scope Normative References Classification and Code Number Order Contents Dimension, Appearance, Weight and Allowable Deviation Technical Requirements Test Method Inspection Rules Packing, Mark and Quality Certificate Reference Page 2 of 12

3 Foreword The consistent degree between this standard and ISO 4997:1999 Cold-reduced Steel Sheet of Structural Quality is not equivalent. This standard replaces GB/T Cold-rolled Plain Carbon and Low Alloy Structural Steel Sheets and Strips. Compared with the previous standard, the main changes in this standard are as follows: -- the thickness range is modified as "not be greater than 3mm"; -- the order contents is added; -- the supply state and requirements of oiling the surface for the steel sheets and steel strips are added; -- the designation and chemical composition of steel are modified; -- the gauge length of measuring post-fracture elongation rate is modified, and the post-fracture elongation rate is reset; -- the surface quality for steel strips is classified, allowable malformation is reduced to 6% from 8%. This standard was proposed by China Iron and Steel Association. This standard shall be under the jurisdiction of National Technical Committee on Iron and Steel of Standardization Administration of China. The main drafting organizations of this standard: Angang Steel Company Limited, Metallurgical Information and Standardization Institute and Guangdong Entry-Exit Inspection and Quarantine Bureau. Chief drafting staffs of this standard: Wang Yue, Wang Xiao Hu, Chen Yue, Piao Zhimin, Li Chengming. This standard was issued in 1989 for the first time. Page 3 of 12

4 Cold-rolled Sheets and Strips of Carbon Structural Steels 1 Scope This standard specifies the dimension, appearance, weight and allowable deviation, technical requirements, test methods, test rules and mark, package, transportation, reposition as well as the Certification of Quality for the cold-rolled sheets and strips of carbon structural steels. This standard is applicable to the cold-rolled sheets and strips of carbon structural steels of which the thickness is not greater than 3mm and the width is not less than 600mm. The single cold-rolled sheet may also refer to this standard for implementation. 2 Normative References The following documents contain the provisions which, through reference in this text, constitute the provisions of this standard. For dated reference, subsequent amendments (excluding corrigendum) or revisions of these publications do not apply. However, all parties who enter into agreement according to this standard are encouraged to study whether the latest edition of these documents is applicable. For undated references, the latest edition of the normative document is applicable to this standard. GB/T 222 Permissible tolerances for chemical composition of steel products GB/T Methods for chemical analysis of iron, steel and alloy - The diantipyrylmethane phosphomolybdate gravimetric method for the determination of phosphorus content GB/T Methods for chemical analysis of iron, steel and alloy - The cupferron separation-chrome azurol S photometric method for the determination of aluminium content GB/T Methods for chemical analysis of iron, steel and alloy - The ammonium persulfate oxidation volumetric method for the determination of chromium content GB/T Methods for chemical analysis of iron, steel and alloy - The sodium Page 4 of 12

5 thiosulfate separation iodimetric method for the determination of copper content GB/T Methods for chemical analysis of iron steel and alloy - The neocuproine-chloroform extraction photometric method for the determination of copper content GB/T Methods for chemical analysis of iron, steel and alloy - The extraction seperation - The dimethylglyoxime spectrophotometric method for the determination of nickel content GB/T Methods for chemical analysis of iron, steel and alloy - The hypophosphite reduction-iodimetric method for the determination of arsenic content GB/T Methods for chemical analysis of iron steel and alloy - The indophenal blue photometric methods for the determination of nitrogen content after distillation separation GB/T Methods for chemical analysis of iron, steel and alloy - The sodium arsenite-sodium nitrite titrimetric method for the determination of manganese content GB/T Methods for chemical analysis of iron, steel and alloy - The reduced molybdoantimonyl phosphoric acid photometric method for the determination of phosphorus content GB/T Methods for chemical analysis of iron, steel and alloy - The perchloric acid dehydration gravimetric method for the determination of silicon content GB/T Methods for chemical analysis of iron, steel and alloy - The sodium (potassium) periodate photometric method for the determination of manganese content GB/T Methods for chemical analysis of iron, steel and alloy - The flame atomic absorption spectrometric method for the determination of manganese content GB/T 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 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 Methods for chemical analysis of iron, steel and alloy - The alumina Page 5 of 12

6 chromatographic separation-barium sulfate gravimetric method for the determination of sulphur content GB/T 228 Metallic materials - Tensile testing at ambient temperature (GB/T , eqv ISO 6892:1998) GB/T 232 Metallic materials - Bend test (GB/T , eqv ISO 7438:1985) 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 2975 Steel and steel products - Location and preparation of test pieces for mechanical testing (GB/T , eqv ISO 377:1997) GB/T 4336 Standard test method for spark discharge atomic emission spectrometric analysis of carbon and low-alloy steel (routine method) GB/T Steel and steel products - General technical delivery requirements (GB/T , eqv ISO 404:1992) GB/T Steel and iron - Sampling and preparation of samples for the determination of chemical composition (GB/T , ISO 14284:1996, IDT) 3 Classification and Code Number 3.1 According to the surface quality, the steel sheets and steel strips are divided into: the higher grade surface the highest grade surface FB FC 3.2 According to the surface structure, the steel sheets and steel strips are divided into: Glossy surface B: Be characterized by finishing rollers with a grinder. Rough surface D: Be characterized by achieving the shot blasting after roll grinder process is finished. 4 Order Contents 4.1 The customer shall provide the following information while ordering: Page 6 of 12

7 a) Serial Number of Standard; b) Product name (steel sheets or steel strips); c) Designation; d) Dimension; e) Dimension and the accuracy of unevenness; f) Coil size (internal diameter and external diameter); g) Weight; h) Grade of surface quality; i) Rim condition (Edge Cutting, EC; Mill Edge, EM); j) Packing manner; k) Purpose; l) Special requirements (the requirements which are not specified in this standard). 4.2 If the information related to dimension and the accuracy of unevenness, grade of surface quality, rim condition and packing manner are not noted in the purchase contract, then the products in this standard shall be supplied according to the ordinary grade's dimension and accuracy of unevenness, the higher grade surface quality of edge cutting steel sheets or steel strips, and the packing manner shall be adopted according to the requirements of supplier. 5 Dimension, Appearance, Weight and Allowable Deviation The dimension, appearance, weight and allowable deviation of the steel sheets and steel strips shall meet the requirements of GB/T Technical Requirements 6.1 Designation and chemical composition The designation and chemical composition (heat analysis) of steel shall be in accordance with those specified in Table 1. Page 7 of 12

8 Q235 Transverse 1a Q275 Transverse 1a a Width of test sample B 20mm; takes B=20mm when carrying out referee test. b a is the thickness of test sample In the case of Supplier guarantee the flexural property, this test can be omitted. 6.5 Surface quality There is no harmful defect on the surface of steel sheets and steel strips, such as bubble, crackle, scarring, folding and inclusion. No lamination shall be existed in the steel sheets and steel strips Surface quality level characteristic of steel sheets and steel strips as shown in Table 4. Table 4 Level Name Characteristic FB High surface level Less fault which does not affect the moldability on the surface is allowed, such as air marking, small scratch, roll marks, slight scuff and oxidation tint, etc. FC Higher surface Fault on the better side of both sides of product shall be limited, no visible level fault; and the other side shall meet the requirements of FB surface level For the continuous process of steel strips, partial surface defect is difficult to find and remove, so the delivery with defects is allowable, however, the defective part shall not exceed 6% of the total length. 7 Test Method 7.1 Inspection items, sampling quantity, sampling procedure and test method of each batch of steel sheets and steel strips shall meet the requirements of Table 5. No. Table 5 Inspection Items, Sampling Quantity and Test Method Sampling quantity Inspection items Sampling procedure Test method (piece) 1 Chemical composition 1 per batch GB/T GB/T 233, GB/T Tension test 1 GB/T 2975 GB/T Bending test 1 GB/T 2975 GB/T Surface quality of steel sheets and steel strips will be carried out visual inspection. Page 10 of 12

9 8 Inspection Rules 8.1 Inspection and acceptance of steel sheets and steel strips shall be carried out by the technical and quality supervision department of the Supplier, and the Buyer has the right to inspect and accept any inspection item according to the provisions of this standard or contract. 8.2 Steel sheets and steel strips shall be accepted by batch, each batch shall be composed by the steel sheets and steel strips with the same designation, furnace number, specification and technology system, and batch weight shall not be greater than 60t. 8.3 Review and determination of steel sheets and steel strips shall meet the requirements of GB/T Packing, Mark and Quality Certificate Packing, mark and the Certification of Quality of steel sheets and steel strips shall meet the requirements of GB/T 247. The type of the Certification of Quality of steel sheets and steel strips shall meet the requirements of GB/T Page 11 of 12