Q/BQB 413-2009 Continuously cold-rolled high strength interstitial free steel sheet and strip
1 Scope
This standard specifies the terms and definitions, classification and codes, dimensions, shapes, weights, technical requirements, inspection and tests, packaging, marking and inspection document for continuously cold-rolled high strength interstitial free steel sheet and strip.
This standard is applicable to continuously cold-rolled high strength interstitial free steel sheets and strips with a thickness ranging from 0.50mm to 2.5mm produced by Baoshan Iron and Steel Co., Ltd. (hereinafter referred to as "steel sheets and strips”).
2 Normative references
The following referenced documents are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 222-2006 Permissible tolerances for chemical composition of steel products
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 2523-2008 Measuring method of surface roughness and peak count for cold-rolled metal sheet (strip)
GB/T 4336-2002 Standard test method for spark discharge atomic emission spectrometric analysis of carbon and low-alloy steel (routine method)
GB/T 5027-2007 Metallic materials - Sheet and strip - Determination of plastic strain ratio
GB/T 5028-2008 Metallic materials - Sheet and strip - Determination of tensile strain hardening exponent
GB/T 8170-2008 Rules of rounding off for numerical values & expression and judgement of limiting values
GB/T 20066-2006 Steel and iron - Sampling and preparation of samples for the determination of chemical composition
GB/T 20123-2006 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method)
GB/T 20125-2006 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method
GB/T 20126-2006 Unalloyed steel - Determination of low carbon content - Part 2: Infrared absorption method after combustion in an induction furnace (with preheating)
Q/BQB 400 Package, mark and inspection document for cold-rolled product
Q/BQB 401 Dimension, shape, weight and tolerances for cold-rolled steel sheet and strip
3 Terms and definitions
3.1
high strength interstitial free steels (Y)
steels whose composition is controlled to achieve improved plastic strain ratio (r value) and strain hardening exponent (n value). These steels have both a high mechanical strength and an excellent suitability for cold forming due to their solid solution hardening and interstitial free microstructure. They are used for complex components involving deep drawing processes
4 Classification and code
4.1 Steel sheets and strips classified according to their purposes shall meet the requirements of Table 1.
Contents
1 Scope
2 Normative references
3 Terms and definitions
4 Classification and code
5 Required information for order
6 Dimensions, shape, weight and tolerances
7 Technical requirements
8 Inspection and test
9 Packaging, marking and quality certificate
10 Rules of rounding off for numerical values
11 Comparison of approximate designations
Annex A (Informative) Comparison table of approximate designations of this standard with domestic and foreign relevant standards
Additional explanation
