It refers to the processing of steel plates or strips into various types of steel through cold drawing, cold bending, and cold drawing at room temperature. Advantages: fast forming speed, high output, and does not damage the coating, can be made into a variety of cross-sectional forms to meet the needs of the use conditions; cold rolling can cause large plastic deformation of the steel, thereby improving the yield of the steel point. 1. Although there is no thermal plastic compression during the forming process, there are still residual stresses in the section, which will inevitably affect the overall and local buckling characteristics of the steel ; 2. The cold-rolled steel section is generally open section, which makes the section’s free torsional stiffness Lower. It is prone to torsion during bending, and it is prone to bending and torsion buckling under compression, and its torsion resistance is poor; 3. The wall thickness of cold-rolled steel is small, and there is no thickening at the corners where the plates are connected, which bears localized The ability to concentrate loads is weak.