Object of Heat Treatment

Object of Heat Treatment:

        The Metals and alloys are heat treated to improve their mechanical properties, to relieve stresses (or) to improve their machinability. The properties of carbon steels can also be altered significantly by subjecting them to heat treatment processes. Heat treatment consists of three basic steps:

(i) Heat the metal/alloy to a predetermined temperature. This temperature will, ideally depends upon the actual composition of carbon steel (i.e., carbon percentage),

(ii) Soaking or holding the metal/alloy at that temperature for some time, so that the temperature across the entire cross-section becomes uniform, and

(iii) Cooling the metal/alloy at a predetermined rate in a suitable medium like water, oil or air. The rate of cooling is the most important factor.