Kylmätyöstön

Kylmätyöstöön, or cold working in English, refers to the plastic deformation of metals at temperatures below their recrystallization point. This process is performed at or near room temperature and typically involves applying significant force to shape the metal. Common cold working processes include rolling, drawing, forging, bending, and extrusion.

The primary advantage of cold working is that it can produce components with superior surface finish and dimensional accuracy compared to hot working. It also increases the tensile strength, yield strength, and hardness of the metal due to work hardening. However, cold working also reduces ductility and can introduce residual stresses into the material.

Metals suitable for cold working generally possess good ductility and malleability at room temperature. Examples include low-carbon steels, aluminum alloys, copper alloys, and some stainless steels. The extent of deformation possible is limited by the material's ductility; excessive cold working can lead to fracture.

After cold working, many metals require annealing, a heat treatment process, to relieve the induced stresses and restore ductility, making further cold working possible or preparing the part for subsequent operations. The choice of cold working method depends on the desired final shape, the material properties, and the required tolerances.