Detail of Q/BQB 403-2003

Introduction of Q/BQB 403-2003

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. Tandem Cold Rolling Low-carbon Steel Sheet and Strip 1 Scope This standard specifies such requirements of tandem cold rolling low-carbon steel sheet and strip as classification and code, dimension, appearance, weight, technical requirements, inspection and test as well as packaging, marking and quality certificate. It is applicable to tandem cold rolling low-carbon steel sheet and strip (hereinafter referred to as steel sheet and strip) with thickness of 0.30mm to 3.5mm produced by Baoshan Iron and Steel Co., Ltd. 2 Normative References The following documents contain provisions which, through reference in this standard, constitute provisions of this standard. For dated reference, subsequent amendments (excluding corrections) to, or revisions, of any of these publications do not apply to this standard. 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 of the normative document referred to applies. GB 222-1984 Method of Sampling Steel for Determination of Chemical Composition and Permissible Variations for Product Analysis GB/T 223 Methods for Chemical Analysis of Iron, Steel and Alloy GB/T 228-2002 Metallic Materials - Tensile Testing at Ambient Temperature GB/T 2975-1998 Steel and Steel Products - Location and Preparation of Test Pieces for Mechanical Testing GB/T 5027-1999 Metallic materials - Sheet and Strip: Determination of Plastic Strain Ratio (r-values) GB/T 5028-1999 Metallic Materials - Sheet and Strip: Determination of Tensile Strain Hardening Exponent (n-values) GB/T 8170-1987 Rules for Rounding off of Numerical Values Q/BQB 400-2003 Packaging, Marking and Quality Certificate of Cold-rolled Products Q/BQB 401-2003 Dimension, Appearance, Weight and Tolerance of Tandem Cold Rolling Cold-rolled Steel Sheets and Strips SAE J911-1998 Method for Measuring Surface Roughness and Peak Number of Cold-rolled Steel Sheets 3 Classification and Code 3.1 The classification of steel sheets and strips in term of the usage is in accordance with the requirements as specified in Table 1. Table 1 Designation Usage DC01 (St12) For general purpose DC03 (St13) For drawing DC04 (St14, St15) For deep drawing DC05 (BSC2) For special-deep drawing DC06 (St16, St14 –T, BSC 3) For super-deep drawing Note: The designations in parentheses can be used until the end of 2005. 3.2 The classification of steel sheets and strips in term of the surface quality is in accordance with the requirements as specified in Table 2. 3.3 The classification of steel sheets and strips in term of the surface structure is in accordance with the requirements as specified in Table 3. Table 2 Grade Code Relatively advanced finishing surface FB (O3) Advanced finishing surface FC (O4) Super-advanced finishing surface FD (O5) Table 3 Surface structure Code Dot surface D Bright surface B 4 Information Needed in Ordering 4.1 The user should provide the following information when ordering: a) product name b) the product standard number c) designation d) product specification, dimension and unevenness accuracy e) edge condition f) surface structure g) surface quality grade h) packaging mode i) usage 4.2 If information, e.g. dimension & roughness precision, surface structure, surface quality grade, edge condition and packaging mode, is not specified in the order contract, the product of this standard shall be supplied as trimmed steel sheets and strips in common dimension & roughness precision, of dot surface and Grade FB surface quality, and shall be packaged in the mode given by the Supplier. 5 Dimension, Appearance, Weight and Tolerance The dimensions, appearance, weight and tolerance of steel sheets and strips shall meet the requirements specified in Q/BQB 401. 6 Technical Requirements 6.1 Chemical composition 6.1.1 The chemical composition of the steel (melting analysis) shall meet the requirements specified in Table 4. Table 4 Designation Chemical composition % C Mn P S Alt a Ti b DC01 (St12) ≤0.10 ≤0.50 ≤0.035 ≤0.025 ≥0.020 — DC03 (St13) ≤0.08 ≤0.45 ≤0.030 ≤0.025 ≥0.020 — DC04 (St14, St15) ≤0.08 ≤0.40 ≤0.025 ≤0.020 ≥0.020 — DC05 (BSC2) ≤0.008 ≤0.30 ≤0.020 ≤0.020 ≥0.015 ≤0.20 DC06 (St16, St14 –T, BSC 3) ≤0.006 ≤0.30 ≤0.020 ≤0.020 ≥0.015 ≤0.20 a For Designations DC01, DC03 and DC04 and when C≤0.01, Alt≥0.015 . b Part of Ti may be replaced with Nb, in which case the total content of Nb and Ti is ≤0.20. 6.1.2 The tolerance of the chemical composition of the finished steel sheet and strip shall meet the requirements of GB/T 222. 6.2 Smelting method The steel used for steel sheet and strip shall be smelted in oxygen converter or electric furnace. 6.3 Delivery condition 6.3.1 After the steel sheet and strip are tandem cold-rolled, they are delivered after annealing and leveling. 6.3.2 The steel sheets and strips shall be delivered oiled, and the oil film shall be removable with aqueous alkali. Under general non-naked packaging, transportation, handling and storage conditions, the Supplier shall ensure the products to be free from rust within 6 months from the day of manufacture. As required by the Demander and noted in the contract based on the agreement of both the Supplier and the Demander, delivery in oiled state may not be adopted.

Contents of Q/BQB 403-2003

1 Scope 2 Normative References 3 Classification and Code 4 Information Needed in Ordering 5 Dimension, Appearance, Weight and Tolerance 6 Technical Requirements 7 Inspection and Test 8 Packaging, Marking and Quality Certificate 9 Rules for Rounding off of Numerical Values Annex A (Informative) Comparison Table of Similar Designations in this Standard and Adopted Standards as well as Relevant Standards Additional Explanation