Carburizing and Nitriding, both are Heat treatment processes used for ' surface hardening' of the low carbon steels (especially) and also low alloy steels, medium and high carbon steels. The main difference is, in Carburizing Carbon is made to diffuse through the metal surfaces whereas in Nitriding, Nitrogen is made to diffuse. Application : Carburizing is applied to low-carbon metals, and metals that are in contact with a high-carbon gas, liquid or solid, gears, crankshafts, camshafts Typical applications of Nitriding include gears, crankshafts, camshafts, cam followers, valve parts, inj