Process of Case Hardening Steel & Metals: What is Case Hardening?

Case hardening is a heat treatment technique in which the steel surface is processed by the addition of carbon. Case hardening of steel is used for numerous applications including for the manufacture of carbon steel forgings and carbon steel pinions. Alloy steels are normally case hardened to increase the metal characteristics. The outer layer of case hardening steel becomes hard, while the inner core remains soft and workable.