The difference between cold rolled and hot rolled steel is not in the smelting process, but in the rolling temperature, or the rolling temperature. The finish rolling temperature is lower than the recrystallization temperature of the steel to become Flat Steel Bar. Hot rolled steel is easy to roll, steel rolling efficiency is high, but hot rolling conditions, steel oxidation, the product surface is dark gray. Flat Steel Bar requires high rolling mill power, rolling efficiency is low, and the rolling process in order to eliminate the work hardening also intermediate annealing, so the cost is higher, but the cold-rolled steel surface bright, good quality, can be directly used to process Finished, so Flat Steel Bar plate is widely used.
Flat Steel Bar is Flat Steel Bar production. Cold rolling is a steel sheet in which the No. 1 steel sheet is further rolled to a desired thickness at room temperature. Compared with hot-rolled steel, cold-rolled steel plate thickness is more accurate, and the surface is smooth, beautiful, but also has a variety of superior mechanical properties, especially the processing performance. Because the cold rolled original roll is more brittle, not suitable for processing, so usually Flat Steel Bar plate after annealing, pickling and surface after leveling to the customer. The maximum thickness of cold rolling is 0.1 - 8.0MM the following, such as most of the cold-rolled steel plate thickness is 4.5MM below; minimum thickness, width is based on the plant's equipment capacity and market demand and decide.
The hot rolled coil was used as raw material, and the iron oxide was removed by pickling and then subjected to cold rolling. The finished product was rolled hard rolled, and the hardness and hardness of the hard rolling were increased due to the cold hardening caused by continuous cold deformation. , So stamping performance will deteriorate, only for simple deformation of the parts. Rolling hard rolls can be used as raw materials for hot-dip galvanizing plants, since hot-dip galvanizing units are equipped with annealing lines. Rolling hard roll weight is generally 6 to 13.5 tons, coil at room temperature, hot rolling acid scrubbing continuous rolling. The inner diameter is 610mm.