martempering Oils

Martempering and marquenching are terms often associated with hot oil quenching. Formally, martempering (full martempering, true martempering) is a term applied when an austenitized work piece is quenched into a medium whose temperature is essentially maintained in a bath just above the martensite start (Ms) temperature of the steel and held in that medium until its temperature is uniform throughout - but not long enough to permit bainite (or pearlite) formation - and then allowed to cool in air. When the martempering process is applied to carburized material, the controlling martensite start temperature is that of the case and as such this process variation is called marquenching.