People always talk about the cold rolled steel and hot rolled steel. But what cold rolled steel really is and how to make it? For this product, the hot rolled coil is the base material. Use this material to make it get through acid washing to rid the roll scale, then do the processing of tandem cold rolling, finally electrolytic-cleaning and annealing and etc.
Cold Rolled Steel Characteristic
The characteristics of them are not been through annealing heat treatment, its hardness is high, HRB is bigger than 90, and the mechanical properties are bad.
In this technics processing, it was processed by the hot rolled steel sheet at the condition for room temperature. Although the steel sheet temperature will get raise due to the rolling processing, we still called this processing as Cold Rolling.
The most popular way for cold rolled is longitudinal rolling. And the production process for it including ready material, acid washing, rolling, degreasing, annealing and etc. In cold rolling, the base material is hot rolled product. Before rolling, the material must wipe out the phosphorus to make sure the surface clean of cold rolled product. The rolling is the important processing to make material deformation. The purpose of degreasing is to wipe out the grease on the material to keep steel surface clean in the annealing.
Cold rolled steel is steel which has been rolled at room temperature, below its recrystallization temperature. Compare with hot rolled steel sheet, the thickness of cold rolled steel sheet is more precise, and the surface is more beautiful and smooth. Before the rolling, the cold rolled steel sheet does not get through heat treatment processing.
The production line for cold rolling is long with many machines and complex technics. And because of the steel surface is easily get the oxidized scale in the high-temperature condition, the surface of hot rolling steel is raggedness. So must use the steel with a clean surface, good shape and mechanical properties, take hot rolled product as material to produce it with cold rolling way.
And there are lots of applications for cold rolled steel. Such as automobile production, electrical products and etc.