Külmvaltsimise

Külmvaltsimine, also known as cold rolling, is a metalworking process that involves passing metal through rollers at or near room temperature. This process differs from hot rolling, where metal is heated to a high temperature before being rolled. Cold rolling is typically performed on metal that has already been hot-rolled and pickled to remove surface scale.

The primary purpose of cold rolling is to improve the mechanical properties of the metal. The deformation that occurs at lower temperatures significantly increases the strength and hardness of the material through a process called strain hardening. This also leads to a more refined grain structure, which contributes to improved surface finish and dimensional accuracy. Cold-rolled products often exhibit a smooth, matte surface, and possess tighter tolerances compared to their hot-rolled counterparts.

Cold rolling is used to produce a variety of metal products, including sheets, strips, bars, and rods. These materials find applications in numerous industries, such as automotive, aerospace, construction, and manufacturing, where precise dimensions, superior surface quality, and enhanced mechanical strength are required. Common metals processed through cold rolling include steel, aluminum, copper, and brass. While effective, cold rolling requires more force than hot rolling due to the increased resistance of the metal at lower temperatures, and it can also induce internal stresses within the material, which may necessitate subsequent annealing processes.