Since the steel contains a high content of Cr, C, and other alloying elements, the tendency of hardened steel is obvious, the weldability is poor. Steel is a flat-shaped, rectangular, or cut directly rolled wide strips made from. 1. The plate thickness divided by thin steel <4 mm (the thinnest 0.2 mm), 4 to 60 mm thick steel plate, thick steel plate from 60 to 115 mm sheet width of 500 to 1500 mm;. Thick width of 600 to 3000 mm thick steel plate and sheet steel grades substantially the same. In all aspects of products, in addition to varieties bridge plate, boiler plate, automobile manufacturing steel, pressure vessel steel plate and pressure vessel steel and other purely multilayer slab outside, some varieties, such as automobile beam steel sheet (thickness of 2.5 to 10 mm), the pattern steel sheet (thickness of 2.5 to 8 mm), stainless steel species, heat-resistant steel plate is a thin plate with a cross. 2. Press the rolled steel sub, sub hot-rolled and cold.