Cold-rolled steel plate
Cold-rolled steel sheet: using hot-rolled steel coil as raw material, after pickling to remove the oxide, cold continuous rolling, the finished product is rolled hard coil, because of the cold hardening caused by continuous cold deformation, the strength and hardness of the rolled hard coil increase, the toughness and plastic index decline, so the stamping performance will deteriorate, can only be used for simple deformation parts.
Rolled hard coil can be used as raw material in hot dip galvanizing plant, because hot dip galvanizing units are equipped with annealing lines.
The rolled hard coil weight is generally 6~13.5 tons, and the steel coil is continuously rolled for hot rolled pickling coil at room temperature. The inner diameter is 610mm.
Product features:
Because it has not been annealed, its hardness is very high (HRB greater than 90), the machining performance is very poor, and only a simple directional bending process of less than 90 degrees (perpendicular to the winding direction) can be carried out.
To put it simply, cold rolling is a process rolled out on the basis of hot rolled coil, generally speaking, it is a process of hot rolling – pickling – cold rolling.
Cold rolling is processed by hot rolled plate at room temperature, although the steel plate will also heat up during the processing process because of rolling, it is still called cold rolling.
Because of the continuous cold rolling, the mechanical properties of cold rolling are poor and the hardness is too high. Must be annealed to restore its mechanical properties, not annealed called rolled hard roll. Rolled rolls are generally used to make products without bending and stretching.
Hot rolled steel plate
In hot rolling, slab (mainly continuous casting billet) is used as raw material to make strip steel by roughing mill and finishing mill after heating. The hot steel strip from the last finishing mill is cooled to the set temperature by laminar flow, and is rolled into steel strip coils by the coiler. The cooled steel strip coils are processed by different finishing lines (leveling, straightening, cross-cutting or longitudinal cutting, inspection, weighing, packaging and marking, etc.) according to the different needs of users. To put it more simply, a piece of billet is heated (that is, the red and hot block of steel that is burned on TV) and then rolled several times, and then trimmed and straightened into a steel plate, which is called hot rolling.
