Marquenching, also known as martempering, is a heat treatment process in which steel components are austenitized and then quenched into a temperature-controlled quenching medium maintained just above the martensite transformation range. The components are held until the temperature becomes uniform throughout the cross-section before being air cooled. This controlled cooling sequence significantly reduces thermal stresses that commonly occur during conventional quenching.

The process is widely selected for precision components requiring high hardness while minimizing distortion, residual stresses and the risk of quench cracking. Marquenching is particularly beneficial for complex geometries and close-tolerance engineering parts.