Induction Hardening
Induction hardening
The steel component is placed inside a coil, which carries a high frequency current. Eddy currents are
induced on the surface of the component causing a rapid rise in temperature. This allows a change to
austenite in the surface layers of the component. Water jets then cool the steel transforming the
austenite to martensite. This leaves the outer surface hard. The frequency of the current determines
the depth of heating and the depth of hardening. Induction hardening is used on the slideways of a
lathe.