GB/T912-1989 Hot-rolled carbon structure and low alloy steel plate and strip
GB/T912-1989 is a technical specification issued by Chinas National Standardization Management Committee specifically for hot-rolled carbon structure and low alloy steel plate and strip. It regulates the requirements, test methods, inspection rules and packaging, transportation and storage of hot-rolled carbon structure and low alloy steel plate and strip.
This specification applies to hot-rolled carbon structure and low alloy steel plate and strip (hereinafter referred to as steel plate and steel strip) with nominal thickness not exceeding 200 mm, which are used to manufacture buildings, bridges, ships, vehicles and pressure vessels. In addition, steel strips for oil pipelines shall also comply with the provisions of this standard. It is not applicable to hot rolled steel plates and steel strips for automobiles, etc. where specific requirements are required.
The chemical composition of steel plates and steel strips should meet the requirements of GB/T700-1988. The test pieces for tensile test shall be cut from the center of the end or edge of the steel plate, straight or round sample for tensile test, straight sample for bending test. The dimension, shape and sample size of the steel plate and strip shall conform to the requirements of GB/T228-1987.
The test methods, inspection rules and packaging, transportation and storage of steel plate and strip shall conform to the requirements of GB/T222-1984 and GB/T2520-1980.
The performance requirements of steel plate and strip are as follows:
1. Tensile strength (σb): Not less than 245 MPa, better than 265 MPa;
2. Yield strength (σ0.2): Not less than 185 Mpa, better than 205 Mpa;
3. Elongation (δ5): Not less than 19%, better than 21%;
4. Bending angle: The angle of the corner of the steel strip on the side of the nominal thickness shall not exceed 0.20 mm for the steel strip with a thickness of less than or equal to 3mm and 0.35mm for the steel strip with a thickness greater than 3mm.
The steel plates and strips produced according to this standard should obtain the factory product certificate. The manufacturer should also provide the customer with the basic performance certificate of the delivered products. The quality of the steel plates and strips as well as the origin or other relevant information should be indicated in the certificate.
