The main differences between hot-rolled and cold-rolled plates: Production process, physical properties, uses, and surface quality.

Production process
‌1. Hot-rolled plate: Hot-rolled plates are made from continuous casting slabs or initial rolled slabs. After being heated in a step-beam heating furnace, they are rolled in a roughing mill and a finishing mill. The rolling temperature of hot-rolled plates is high, the deformation resistance is small, and a large deformation amount can be achieved. The thickness of hot-rolled plates is generally between 1 and 20 mm. ‌

‌2. Cold-rolled plates: Cold-rolled plates are rolled at room temperature without a heating process. The thickness of cold-rolled plates is thinner, usually between 0.18 mm and several millimeters. The cold rolling process is more complicated and requires multiple straightening and flattening processes. ‌

Physical properties
‌1. Strength and hardness: The strength and hardness of cold-rolled plates are high, but due to cold work hardening, their toughness and plasticity indicators decrease, and their stamping performance is poor, which is suitable for parts with simple deformation. The hardness of hot-rolled plates is low, but their ductility is good, which is suitable for applications that require large deformation. ‌

‌Surface quality‌:

1. The surface of cold-rolled plate is smooth and has high dimensional accuracy, which is suitable for occasions with high requirements for surface quality.
2. The surface of hot-rolled plate is rough and the dimensional accuracy is relatively low. ‌

Applications
‌1. Hot-rolled plate‌: Mainly used in the production of steel structures, bridges, ships, vehicles, and applications that require good ductility. ‌

‌2. Cold-rolled plate‌: Suitable for occasions with high requirements for surface quality and dimensional accuracy, such as automobile manufacturing, electrical housing, architectural decoration, etc.