Austempering is an isothermal heat treatment process in which steel or cast iron is austenitized and then rapidly quenched into a controlled-temperature salt bath before being held at a constant temperature until a bainitic structure forms.

Unlike conventional quench hardening, austempering minimizes internal stresses and distortion while providing an outstanding balance of strength, ductility, toughness and fatigue resistance.

It is widely selected for safety-critical and wear-resistant engineering components.