This standard specifies the dimension classification, shape, technical requirements, test methods, inspection rules, packing, marking and quality certificate of the cold-rolled quality carbon structural steel sheets and strips.
This standard is applicable to the cold-rolled quality carbon structural steel sheets and strips within thickness no larger than 4 mm for the automobile industry, aviation industry and other departments.
2 Normative References
GB 222 "Method of Sampling Steel for Determination of Chemical Composition and Permissible Variations for Product Analysis"
GB 223 "Methods for Chemical Analysis of Iron, Steel and Alloy"
GB 224 "Determination of Depth of Decarburization of Steel"
GB 228 "Metallic Materials-Tensile Testing"
GB 232 "Metallic Materials - Bend Test"
GB 247 "General Rule of Acceptance, Package, Mark and Certification for Steel Plates (Sheets) and Strips"
GB 699 "Quality Carbon Structural Steels -Technical Requirements"
GB 708 "Dimension Shape Weight and Tolerance for Cold-rolled Steel Plates and Sheets"
GB 2975 "Rules for Sampling in Mechanical and Technological Testing of Steel PGB products"
GB 4156 "Metals; Cupping Testing Method (Thickness 0.2-2mm)"
GB 6394 "Metal-methods for Estimating the Average Grain Size"
GB 6397 "Metallic Materials--Test Pieces for Tensile Testing"
GB/T 13299 "Steel-Determination of Microstructure"
3 Classification and Code Number
3.1 The steel plates (sheets) and strips are divided in three groups according to the surface quality, :
Highest-quality Finished Surface I
Higher-quality Finished Surface II
Ordinary Finished Surface III
3.2 The steel plates (sheets) and strips are divided in 3 levels according to drawing level:
Deepest-drawing Level Z
Deeper-drawing Level S
Regular-drawing Level P
GB/T 13237-1991 The following standards are cited：
