Hot Rolling is a hot rolling process. Hot rolling has the advantages of high production efficiency, large scale, low energy consumption, low cost, high mechanization and automation. It is suitable for mass continuous production and is the most important metal pressure processing method. Hot rolling is widely used because of its low deformation resistance and good plasticity. However, due to the uneven rolling temperature and the existence of oxide scale on the surface, the dimensional accuracy and surface roughness of the products are not as good as those of the cold rolled products. The main equipment of hot rolling is rolling mill.

There are many kinds of rolling mills for hot rolling, such as two-roll mill, three-roll mill, three-roll Lauter mill, four-roll mill, Y-type mill, two-roll skew mill, three-roll skew mill, cross mill, universal mill and various special mills. According to the product variety, product quality requirements, output, site conditions and other factors, there are many forms of rolling mill layout in hot rolling workshop, such as single-machine layout, single-row or multi-row horizontal layout, tracking layout, continuous rolling layout, chessboard layout, etc. The process flow of hot rolling generally includes raw material preparation, heating, rolling, finishing and other major processes. Hot rolling can be used to roll large ingots or billets to produce large size products. For example, large ingots of 70 t_and billets of 50 t can be rolled, thick plates of 500 m m thickness, seamless steel tubes of 1070 mm diameter, 1200 mm 530 mm H section steel and 78 kg/m rail can be produced. In the process of hot rolling, the temperature of the rolled piece decreases gradually, and the deformation resistance of the material increases gradually, which eventually makes hot rolling impossible. Therefore, the size of hot-rolled products can not be too small, only rolling 1 mm thick sheet, 20 mm diameter seamless steel pipe, 5.0 mm diameter wire and so on. 

Hot rolling can have a large production capacity, such as a blooming mill with an annual output of 6 million tons and a hot strip mill with an annual output of 6 million tons. Hot-rolled products can be divided into hot-rolled strip, hot-rolled seamless steel pipe, hot-rolled section steel and hot-rolled special steel according to their cross-section shape characteristics. Hot rolling can be divided into longitudinal rolling, cross rolling and cross rolling.