Q235 is hot rolled steel or cold rolled steel?
Hot rolling and cold rolling are forming processes of profiled steel or sheet steel. They have a great influence on the microstructure and properties of steels. Steel is rolled mainly by hot rolling, and cold rolled only for the manufacture of small sections of steel and thin plates.The advantage of hot rolling is that it can destroy the casting structure of steel ingot, refine the grain of steel, and eliminate the defects of microstructure, so that the steel structure is compact and the mechanical properties are improved. This improvement is mainly reflected along the rolling direction, so that steel is no longer a certain extent, isotropic body; casting formed when bubbles, cracks and loose, can also be welded under high temperature and pressure.
Q235 hot rolling and cold rolling are available, depending on availabilityThe need for heating the material before hot rolling, rolling process or rolling, usually heated to above the recrystallization temperature, such as more than 1000 degrees; cold rolling is the process does not require heating of the material, or the material is heated to the temperature below the recrystallization.
Hot rolling and cold drawing is the difference of the production process of hot rolling is processed at high temperature, does not change the structure and properties of metal at high temperature, cold drawn round will be perforated, then in tube processing machine in the cold drawing, no tempering condition, this process will affect the crystal structure of metals. In general, better than the mechanical properties of cold rolled steel, after heat treatment, the tensile and yield strength, plasticity and toughness will be improved, in addition, heat treatment can eliminate the residual stress, and the cold may be because in the process of the steel yield the non-uniform deformation. The residual stress produced, the residual stress has great influence on the stability of.
