Hot rolling, using slab (mainly continuous casting slab) as raw material, after heating, it is made into strip steel by roughing mill and finishing mill. The hot steel strip from the last finishing mill is cooled to the set temperature by laminar flow and coiled into a steel strip coil by a coiler. According to the different needs of users, the cooled steel strip coil is treated with different finishing lines (leveling, straightening, transverse cutting or longitudinal cutting, inspection, weighing, packaging, marking, etc.). ) become steel plate, flat coil and longitudinal shear steel strip products. Simply put, a billet is heated (that is, a red and hot steel block burned on TV), rolled several times, and then trimmed and corrected into a steel plate. This is called hot rolling.

cold rolling

Cold rolling: the hot rolled steel coil is used as raw material, and then the oxide scale is removed by pickling, and the finished product is hard rolled steel coil. Because of the cold work hardening caused by continuous cold deformation, the strength and hardness of hard rolled coil increase, and the toughness and plasticity index decrease, so the stamping performance will deteriorate and it can only be used for simple deformed parts. Because all hot dip galvanizing units are equipped with annealing units, hot rolled steel coils can be used as raw materials for hot dip galvanizing units. The weight of hard rolled coil is generally 6~ 13.5 tons, and the hot rolled pickling coil is continuously rolled at room temperature. The inner diameter is 6 10 mm.

Product features: Because it has not been annealed, its hardness is very high (HRB is greater than 90) and its machinability is very poor. It can simply bend less than 90 degrees (perpendicular to the winding direction).

Simply put, cold rolling is processed and rolled on the basis of hot rolled coil. Generally speaking, it is a hot rolling-pickling-cold rolling process.

Cold rolling is a hot rolled sheet at room temperature. Although rolling also increases the temperature of the plate during processing, it is still called cold rolling. Due to continuous cold deformation during hot rolling, the mechanical properties are poor and the hardness is too high. It must be annealed to restore its mechanical properties, and those that are not annealed are called hard rolls. Hard coil plate is generally used to make products that do not need to be bent or stretched, and the thickness is lucky to be bent on two sides or four sides below 1.0.

1. Cold rolling is a hot-rolled sheet at room temperature.

2. After a billet is heated (that is, a red and hot steel block burned on TV), it is finely rolled several times, and then trimmed and corrected into a steel plate. This is called hot rolling.