ON THE STABILIZATION OF RETAINED AUSTENITE

Carburized layers in quenched steel components usually contain few percent of retained austenite (RA). Deep freezing treatment by dipping in liquid nitrogen is usually carried out when it is required to reduce the amount of retained austenite to very low levels. Stability of retained austenite due to aging was assessed by the difficulty of transformation of retained austenite to martensite when subjected to sub-zero treatment. In this work the case material was simulated by carburizing thin specimens of 1mm thick to obtain full through hardening by carburization. Retained austenite was found to