Dilatometric Study of the Quench and Partitioning Process

Abstract

A new thermal processing route, Quench and Partitioning (Q&P), has been proposed recently as a way to produce high-strength martensitic steels with good ductility or toughness. It consists of quenching a steel to a suitable temperature and subsequently reheating it to a higher temperature, the so called partitioning temperature. During the latter heat treatment, carbon is rejected from a carbon supersaturated martensitic microstructure into the remaining austenite, stabilizing the latter. The usual formation of carbides on tempering of martensite is suppressed by the presence of Si and/or Al. In the present contribution, the Q&P process is studied by means of dilatometry and differential scanning calorimetry (DSC). The effect of Si and Al on tempering is studied and the implications for Q&P processing are adressed.