Hot-rolling&cold Rolling Steel
Hot rolling is made of slabs (mainly continuous billets) as raw materials. After heating, strips are made from roughing mills and finishing mills. From the last finishing mill stand out of the hot strip laminar cooling through to the set temperature, the coiling machine rolled strip steel roll cooled, according to the different needs of users with different finishing line (flat, straightening, transverse or longitudinal, inspection, weighing, packing and marking etc.) processing and become steel, flat steel product volume and slitting. A simple, a billet after heating (TV is that burning red hot steel block) refined over several rolling cut edge correction plate become, this is called hot.
Cold: hot rolled steel coil as raw material by pickling descaling after cold rolling, the finished rolling hard volumes, due to continuous deformation caused by cold hardening the volume rolling hard strength, hardness, toughness index rise decline, so the stamping performance will deteriorate, only for a simple deformation of parts. Rolled hard rolls can be used as raw material for hot galvanizing plants, because the hot galvanizing units are equipped with annealing lines. The roll weight is usually 6~13.5 tons, and the coil is rolled continuously at room temperature. The inner diameter is 610mm.
Product features: without annealing treatment, the hardness is very high (greater than 90 HRB), the mechanical performance is poor, only a simple bending process is less than 90 degrees direction (perpendicular to the direction of the volume).
To put it simply, cold rolling is rolled out on the basis of hot rolled coils, generally in the process of hot rolling --- acid washing -- cold rolling.