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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard is developed by revision after combining GB 912-2008 Hot-rolled Sheets and Strips of Carbon Structural Steels and High Strength Low Alloy Structural Steels and GB/T 3274-2007 Hot-rolled Plates and Strips of Carbon Structural Steels and High Strength Low Alloy Structural Steels.
This standard replaces GB 912-2008 Hot-rolled Sheets and Strips of Carbon Structural Steels and High Strength Low Alloy Structural Steels and GB/T 3274-2007 Hot-rolled Plates and Strips of Carbon Structural Steels and High Strength Low Alloy Structural Steels. The following main changes have been made with respect to GB 912-2008 and GB/T 3274-2007:
——The delivery length of steel strips with defects allowed is revised as that not exceeding 6% of the total length of each roll of steel strip (see 5.6.4);
——The inherent quality requirements are added (see 5.7);
——The inspection batch weight is expanded and revised as batching by furnace (see 7.2).
This standard was proposed by China Iron and Steel Industry Association.
This standard is under the jurisdiction of SAC/TC 183 National Technical Committee on Iron and Steel of Standardization Administration of China.
The previous editions of standard replaced by this standard are as follows:
——GB/T 912-1989 and GB 912-2008.
——GB/T 3274-1988 and GB/T 3274-2007.
Hot-rolled Plates, Sheets and Strips of Carbon Structural Steels and High Strength Low Alloy Structural Steels
1 Scope
This standard specifies order contents, dimension, shape and weight, technical requirements, test methods and inspection rules as well as packaging, marking and certification of hot-rolled plates, sheets and strips of carbon structural steels and high strength low alloy structural steels.
This standard is applicable to hot-rolled plates, sheets and strips of carbon structural steels and high strength low alloy structural steels with the thickness no greater than 400 mm (hereinafter referred to as steel plates, sheets and strips).
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 228.1 Metallic Materials - Tensile Testing - Part 1: Method of Test at Room Temperature
GB/T 229 Metallic Materials - Charpy Pendulum Impact Test Method
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 700 Carbon Structural Steels
GB/T 709 Dimensions, Shape, Weight and Tolerances for Hot-rolled Plates and Sheets
GB/T 1591 High Strength Low Alloy Structural Steels
GB/T 2975 Steel and Steel Products - Location and Preparation of Test Pieces for Mechanical Testing
GB/T 8170 Rules of Rounding Off for Numerical Values & Expression and Judgement of Limiting Values
GB/T 14977 General Requirement of Surface Finish for Hot Rolled Steel Plates
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
3 Order Contents
3.1 The contract or order ordered according to this standard shall include the following contents:
a) Standard No.;
b) Product name (steel plates, sheets or strips);
c) Designation;
d) Delivery condition;
e) Dimension and accuracy;
f) Edge condition (trimmed EC and untrimmed EM);
g) Weight;
h) Special requirements.
3.2 Generally, the steel plates (sheets) sheared from steel strips are delivered in trimmed status; if the edge condition is not indicated in the order contract, generally untrimmed steel strips are delivered.
4 Dimension, Shape and Weight
The dimension, shape, weight and permissible deviation of steel plates, sheets and strips shall meet the requirements of GB/T 709.
5 Technical Requirements
5.1 Designation and chemical component
The designation and chemical component (heat analysis) of steels shall meet the requirements of GB/T 700 and GB/T 1591. The permissible deviation for chemical component of finished steel plates, sheets and strips shall meet the requirements of GB/T 222.
5.2 Smelting process
Steels shall be smelted with oxygen converter or electric furnace.
5.3 Delivery condition
Steel plates, sheets and strips shall be delivered in hot-rolled, control-rolled or heat treatment condition.
5.4 Mechanical property
5.4.1 The tensile strength and percentage elongation after fracture of steel plates, sheets and strips with thickness less than 3 mm shall meet the requirements of GB/T 700 and GB/T 1591, and the percentage elongation after fracture is permitted to be 5% (absolute value) less than that specified in GB/T 700 or GB/T 1591. As required by the Demander, the yield strength of steel plates, sheets and strips may be in accordance with the requirements of GB/T 700 and GB/T 1591.
5.4.2 The mechanical and processing properties of steel plates, sheets and strips with thickness no less than 3 mm shall meet the requirements of GB/T 700 and GB/T 1591.
5.5 Processing property
180° bend test shall be carried out for steel plates, sheets and strips, and the bending pressure head diameter of the specimen shall meet the requirements of GB/T 700 and GB/T 1591. The inspection may not be carried out if the Supplier can ensure steel plates, sheets and strips can pass the cold bend test.
Foreword i
1 Scope
2 Normative References
3 Order Contents
4 Dimension, Shape and Weight
5 Technical Requirements
6 Test Methods
7 Inspection Rules
8 Packaging, Marking and Certification
