What is the process flow of cold-rolled steel coils?

Cold-rolled steel coils are usually rolled longitudinally. The process of cold rolling production generally includes raw material preparation, pickling, rolling, degreasing, annealing (heat treatment), finishing, etc. Cold-rolled steel coils use hot-rolled products as raw materials. Before cold rolling, the raw materials must be dephosphorized to ensure the surface cleanliness of the cold-rolled products.

Rolling is the main process for deforming materials. The purpose of degreasing is to remove the lubricating grease attached to the rolled material during rolling to avoid contaminating the steel surface during annealing, and also to prevent carbon increase for stainless steel. Annealing includes intermediate annealing and finished product heat treatment. Intermediate annealing is to eliminate the work hardening caused by cold deformation through recrystallization to restore the plasticity of the material and reduce the deformation resistance of the metal.

The purpose of finished product heat treatment is not only to eliminate hardening through recrystallization. It is also to obtain the required organization (such as various textures, etc.) and product performance (such as deep drawing, electromagnetic properties, etc.) according to the technical requirements of the product. Finishing includes inspection, shearing, straightening (flattening), printing, classification and packaging. Cold-rolled steel coils have high packaging requirements to prevent the surface of the product from being scratched during transportation.

In addition to the above processes, there are also special processes for the production of some special products. For example, when rolling silicon steel sheets, decarburization annealing must be performed before cold rolling, and coating, high-temperature annealing, stretch straightening (see tension straightening) and tempering must be performed after rolling.