Case-hardening

The process of hardening the surface of steel while leaving the interior unchanged. Both carbon and alloy steels are suitable for case-hardening, provided that their carbon content is low, usually up to a maximum of 0.2%. Components subject to this process, particularly in the case of alloy steels, have a hard, wear-resistant surface with a tough core. In the case of steel, the carbon content of the surface can be increased by heating in a medium containing carbon, followed by heat treatment.