Hardening
Hardening is a heat treatment process used to increase the hardness and strength of steel and other ferrous alloys by altering their microstructure. The process typically involves heating the material to a temperature above its critical transformation point—usually between 800°C and 900°C (1470°F to 1650°F) depending on the steel grade—where the steel’s crystal structure changes to austenite.
Once the desired temperature is reached and the material is held (soaked) for a specific time to allow uniform heating, it is rapidly cooled or quenched in a medium such as water, oil, or air. This rapid cooling transforms the austenite into a hard, brittle microstructure called martensite.
