5.13 Heat Treatment of Steels
Heat treatment can be defined as an operation or combination of operations involving the heating and
cooling of a metal or alloy in the solid state. Steel properties can more easily be controlled by heat
treatment than by mechanical work.
By heat treatment, steel can be made strong
and hard, or it can be made soft and ductile.
By varying the carbon and alloy contents, and
the heat treatment of steels, a wide range of
mechanical properties can be produced.
Since alloyed steels are more expensive than
plain carbon steels, they are usually heat
treated to take full advantage of their
properties.
What is a heat treatment? Heat treatments
basically consist of a three-step process:
- heating the steel to a specific
temperature
- maintaining the steel at that
temperature for a certain length of
time
- cooling the steel at a specific rate