Hot rolled coil is made of strip steel by roughing mill and finishing mill group after heating with plate defects (mainly continuous casting defects) as raw materials. From finishing the last hot steel strip mill out through laminar flow cooling to the set temperature, which consists of the winder coil, steel coil after cooling, according to the different needs of users, with different finishing line (flat, straightening, transverse or longitudinal cutting, inspection, weighing, packaging and logo, etc.) and become a steel plate, flat roll and longitudinal cutting steel strip products. Hot rolling steel plate products have high trength, good toughness, easy processing and forming and good weldability and other excellent properties, so the north is widely used in ships, automobiles, Bridges, construction, machinery, pressure vessels and other manufacturing industries.