| Fe-25%Ni-0.2%C alloy, Ms temperature of which was controlled to -16℃ so that strain-induced martensite could be transformed at room temperature, was prepared by high frequency induction furnace and plastically deformed to various deformation degrees by rolling at room temperature. Then the aspects of strain-induced martensite transformation, athermal martensite transformation and austenite stabilization were studied. Strain-induced martensite was not produced up to 20% deformation degree. However, in the range of higher deformation degree than 20%, the amount of the martensite increased with increasing deformation degree. The morphology of strain-induced martensite appeared to be massive type, regardless of deformation degree. Athermal martensite, transformed by subzero cooling the deformed austenite, was produced preferentially near the prior strain-induced martensite and the athermal martensite plate became smaller as the deformation degree was increased. The austenite stabilization was increased with deformation degree in transformation of austenite to athermal martensite. |
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