Is the steel coil cold rolled or hot rolled?

Steel coils can be hot rolled or cold rolled, depending on the production process and the desired end product characteristics.

Steel coils can be either cold rolled or hot rolled

Steel coil, also known as coil steel, is formed into a coil by hot or cold pressing of steel, so as to facilitate storage and transportation, and to facilitate various processing, such as processing into steel plates, steel strips, etc. This form applies not only to hot-rolled steel coils, but also to cold-rolled steel coils. Hot-rolled steel coils are produced by high-temperature rolling and are covered with iron oxide scale, while cold-rolled steel coils are produced by low-temperature rolling and have a smooth and flat surface. Therefore, the specific type of steel coil (hot rolled or cold rolled) depends on its production process and final use.

Hot-rolled steel coil: Using continuous casting slab or initial rolling slab as raw material, after heating in a step-beam heating furnace, it is rolled into straight coil. After the straight coil is processed by head cutting, tail cutting, edge cutting and multiple straightening, flattening and other finishing lines, it can become hot-rolled steel plate, flat hot-rolled steel coil, slitting strip and other products. If the hot-rolled finishing coil is pickled to remove the oxide scale and oiled, it becomes a hot-rolled pickled plate coil.

Cold-rolled steel coil: Using hot-rolled steel coil as raw material, after pickling to remove the oxide scale, it is cold-rolled continuously, and the finished product is hard-rolled coil. Due to the cold work hardening caused by continuous cold deformation, the strength and hardness of the hard-rolled coil increase, the toughness and plasticity index decrease, and the stamping performance deteriorates, so it can only be used for parts with simple deformation. Hard-rolled coil can be used as raw material for hot-dip galvanizing plants, because hot-dip galvanizing units are equipped with annealing lines.

In summary, steel coils can be hot-rolled or cold-rolled, depending on their production process and the required final product characteristics.