抄録
Two sorts of stepped quenchig are studied. The first is an austempering-ike quenching, that is before quenching in water, the sample is dipped in a 300°C salt bath for a little while. The secend is characterized by the short time heating beyond A3 point just before queuching.
Hardness distribution curves revoal some interesting, results which conform with structural aspects. Residual strese curves show that the thermal and the transformational stress can be superposed in various ways according to the time of heating boyond A3, or the time of dipping in a 300°C salt bath.
