Pair Cross Type Rolling Mill for Hot Rolling

It has been long recognized that the shape and crown of rolled strips are important for in terms not only of product quality but also of material yield and stable rolling. Furthermore, to raise productivity and to save energy, it is necessary that schedule of rolling, for example thickness, width or materials, is free from constraints. Consequently, it has strongly required that the development of rolling mill to control the shape and crown of rolled strips. A “pair cross type” rolling mill (hereinafter PC mill) has been developed for these requirements. The upper rolls and lower rolls are skewed in a pair which consists of work roll and back-up roll, and PC mills are capable of freely controlling the shape and crown of rolled strips. The first PC mill was put into a practical use at Nippon Steel Corporation Hirohata Works (Now, Nippon Steel & Sumitomo Metal Corporation) in 1984 and PC mills are widely used in the world and they contribute to the achievement of high accuracy and quality of rolled strips through the superior strip crown and flatness controllability.