What is cold rolled steel

Cold rolling refers to a rolling method that uses the pressure of the roller to extrude the steel and change the shape of the steel at normal temperature. Although the steel plate is also heated during processing, it is still called cold rolling. Specifically, the hot rolled steel coil used for cold rolling is used as the raw material, and the finished product is hard rolled steel coil after acid cleaning, scale removal and pressure processing.

Generally, cold-rolled steel, such as galvanized steel and color steel, needs annealing, so its plasticity and elongation are also good, and it is widely used in automobile, household appliances, hardware and other industries. The surface of the cold rolled sheet has a certain degree of smoothness, and it feels very smooth, mainly due to acid pickling. Generally, the surface finish of the hot rolled plate cannot meet the requirements, so the hot rolled steel strip needs to be cold rolled. The minimum thickness of the hot rolled steel strip is generally 1.0 mm, and the cold rolled steel strip can reach 0.1 mm. The hot rolled steel strip is rolled above the crystallization temperature point, and the cold rolled steel strip is rolled below the crystallization temperature point.

The change of steel grade caused by cold rolling belongs to continuous cold deformation. The cold work hardening caused by this process increases the strength and hardness of the rolled hard coil, and decreases the toughness and plasticity index.

For end use, cold rolling deteriorates the stamping performance, and the product is suitable for simple deformed parts.