Frequently asked questions.

Frequently asked questions.

What is hot rolling?

Steel ingots or billets are difficult to deform and process at room temperature. They are generally heated to 1100 to 1250°C for rolling. This rolling process is called hot rolling. The termination temperature of hot rolling is generally 800 to 900°C, and then it is generally cooled in air, so the hot rolling state is equivalent to normalizing treatment. Most steels are rolled by hot rolling.

The steel delivered in the hot-rolled state has a certain degree of corrosion resistance due to the high temperature, so it can be stored in the open air. However, this layer of oxide scale also makes the hot-rolled steel surface rough and the size fluctuates greatly. Therefore, it is required to use hot-rolled semi-finished products or finished products as raw materials and then cold-rolled production of steels with smooth surface, accurate size and good mechanical properties.