What is Hot Rolling and Cold Rolling? Hot rolling:
Hot rolled steel plate is the steel plate that having been hot rolled. That is to have the slab of 1200℃~1300℃ reduced to the required thickness and coiled at the temperature of 500℃~700℃. Black steel coil is the original hot rolled coil without squama removal. No.1 hot rolled coil is the coil that has been annealed and pickled, because of its ivory white surface, it is also called “ivory white steel”. The general thickness of the hot rolling plate is 2.5MM (some can reach 1.2MM) to 150MM, and the Max. thickness of plate coil is 12MM , and those thicker than 12 MM is plate piece. The thickness and width depend on the capability of the manufacturer and the market demand. Cold rolling: Cold rolling steel plate is the steel plate that has been cold rolled. That is to have the NO. 1 steel plate further reduced to the required thickness at room temperature. Compared with hot rolled plate, cold rolled steel sheet has higher accuracy on thickness, smoother and nicer surface finish, and various excellent mechanical properties, especially for processing property. The original cold rolled coil is quite brickle, which is not suitable for processing, thus generally they need annealing, pickling and surface leveling before selling to customers. The thickness range of cold rolled steel is 0.1--8.0MM, and most of the steel has the thickness thinner than 4.5MM. The Min. thickness and width depend on the capability of the manufacturer and the market demand. |
