The main differences between hot rolling and cold rolling are:
1. The cold-rolled steel section is allowed to have local buckling, so as to make full use of the bearing capacity of the rod after buckling; the Hot rolled section does not allow local buckling.
2. The causes of residual stress in hot-rolled and cold-rolled sections are different, so the distribution of residual stress on sections is also very different. The distribution of residual stress on the section of cold-formed thin-wall steel is curved, while the distribution of residual stress on the section of hot-tied or welded steel is a thin film.
3. The free torsional stiffness of the hot-rolled section is higher than that of the cold-rolled section, so the torsional resistance of the hot-rolled section is better than that of the cold-rolled section.
