The Many Types of Thermal Treatment

There are a number of different thermal treatments that are applicable to hardening steels. Notice the chapter title doesn’t say “heat treatments” because as you gather by now, it isn’t heat alone that affects steel’s hardness, structure, usefulness, or longevity qualities. There is also not a common temperature, or a single timing recipe, that applies to all the grades of steel, because each grade of steel has its own unique blend of chemistry. The percentage of carbon to iron, as well as the alloy content and alloy volumes, changes the exact recipe for each grade of steel. The metal must go into solution (Ac3) for heat treatment to occur. Each of the elements have their own melt point that allows the metal to achieve that proper solution, where the elements blend together to make one strong cohesive alloy.