What is the difference between cold rolled sheet and hot rolled sheet?

The mechanical properties of hot-rolled steel sheets are far inferior to those of cold-worked and forged, but they have better toughness and ductility. 

Due to a certain degree of work hardening, the cold-rolled steel plate has low toughness, but it can achieve a better yield ratio, and is used to cold-bend parts such as spring sheets. At the same time, due to the yield point

It is closer to the tensile strength, so there is no predictability of danger during use, and accidents are prone to occur when the load exceeds the allowable load. 

1). The cold plate is processed by cold rolling without scale on the surface, and the quality is good. The hot plate is processed by hot rolling, and the surface has oxide skin, and the thickness of the plate has a difference. 

2). The hot-rolled sheet has poor toughness and surface smoothness, and the price is low, while the cold-rolled sheet has good stretchability and toughness, but the price is more expensive.

3). Rolling is divided into cold rolling and hot rolling, with recrystallization temperature as the distinguishing point.

4). Cold rolling: cold rolling is generally used to produce strips, and its rolling speed is relatively high.

Hot rolling: The temperature of hot rolling is similar to that of forging.

5). The surface of the hot-rolled board without electroplating is dark brown, and the surface of the cold-rolled board without electroplating is gray. After electroplating, it can be distinguished from the smoothness of the surface, and the smoothness of the cold-rolled board is higher than that of the hot-rolled board.