Introduction
The main method for rolling type steel is mainly divided into hot rolling and cold rolling. These two methods can be further divided into different processes. Hot rolling is the process of using mechanical deformation to reduce the thickness and increase the area by subjecting the hot rolled strip to the annealing furnace. This article explains the difference between these two processes.
Cold Rolling
Cold rolling is a process of using mechanical deformation to reduce the thickness and increase the area of steel strip by subjecting the cold rolled strip to the annealing furnace. The temperature of the rolled strip is generally not higher than the recrystallization temperature. In the cold rolling process, the deformation resistance of the rolled strip is mainly determined by its yield strength rather than its plasticity and hot rolling capacity. After cold rolling, the thickness of the cold-rolled strip can be reduced to 0.5～3.5mm, and its width can reach 600～2500mm. Cold rolling can change the shape of the steel strip or sheet see in hot rolling. Because of the hardening effect, the steel becomes softer, ductility decreases and strength increases.
Hot Rolling
Hot Rolling is a process of using mechanical deformation to reduce the thickness and increase the area of steel strip by subjecting the hot rolled strip to the annealing furnace. The temperature of the rolled strip is generally higher than the recrystallization temperature during hot rolling, so the plasticity and hot rolling capacity of the rolled strip affects the deformation resistance during hot rolling. After hot rolling, the thickness of the hot-rolled strip can be reduced to 5～20mm, and its width can reach 1000～3000mm. Hot rolling can improve the elongation and micro-tool of the cold-rolled strip, and can change its shape, increasing the uniformity of the microstructure and mechanical properties. Furthermore, it can reduce the amount of non-metallic inclusions in the steel strip, improve the surface quality of the steel strip and increase the production speed.
Conclusion
In conclusion, the main methods of rolling type steel mainly include hot rolling and cold rolling. Generally, hot rolling can reduce the thickness of the steel strip to 0.5～3.5mm and improve its surface quality, while cold rolling can reduce the thickness of the steel strip to 5～20mm and increase its strength. In addition, hot rolling has a higher production speed than cold rolling and can change the shape of steel more than cold rolling. Therefore, it is necessary to choose the correct method according to the specific processing technology and material requirements.
