difference between heat treatment and hardening
Heat Treatment Processes Hardening. Hardening involves heating of steel, keeping it at an appropriate temperature until all pearlite is transformed into austenite, and then quenching it rapidly in water or oil. The temperature at which austentizing rapidly takes place depends upon the carbon content in the steel used.
I pass this heat treatment definition along until I'm corrected or find a more succinct, better one. Heat treatment is the controlled heating and cooling of a metal in order to change its properties. Forging is controlled heating and cooling but is not considered a heat treatment by metallurgists, probably because of the plastic deformation involved.