Both hot rolling and cold rolling are processes for forming steel sheets or profiles, and they have a great influence on the structure and properties of steel. The rolling of steel is mainly hot-rolled, and cold-rolled is usually only used to produce small-sized sections and sheets with precise dimensions.
The main differences between hot rolling and cold rolling are:
1. Appearance and surface quality:
Since the cold plate is obtained after the cold rolling process of the hot plate, and some surface finishing is carried out at the same time, the cold plate is better than the hot plate in terms of surface quality (such as surface roughness), so if the product is If there are higher requirements for coating quality such as subsequent painting, cold plates are generally selected, and hot plates are divided into pickling plates and non-pickling plates. The surface of the pickling plate has a normal metallic color due to pickling, but it is not Cold rolling, so the surface is still not as high as the cold plate, and the unpickled plate usually has an oxide layer on the surface, a black layer, or a black layer of iron tetroxide. In layman’s terms, it looks like it’s been roasted, and if the storage environment is not good, it usually has a little rust.
2. Performance:
In general, the mechanical properties of the hot plate and the cold plate are considered to be indistinguishable in engineering. Although the cold plate has a certain degree of work hardening during the cold rolling process, (but it does not rule out the strict requirements for mechanical properties. , then it needs to be treated differently), the yield strength of the cold plate is usually slightly higher than that of the hot plate, and the surface hardness is also higher, depending on the degree of annealing of the cold plate. But no matter how annealed, the strength of a cold plate is higher than that of the hot plate.
3. Forming performance
Since the performance of cold and hot plates is basically not too different, the influencing factors of forming performance depend on the difference in surface quality. Since the surface quality is better than cold plates, generally speaking, steel plates of the same material are of the same material. , the forming effect of a cold plate is better than that of a hot plate.
