(S2·31-S095)Mechanical properties of nanocrystalline austenite in Fe-24Ni-0.3C alloy prepared by highpressure torsion and subsequent heat treatment

摘要

Ultrafine grained or nanocrystalline materials have significantly higher strength but limited ductility, inparticular poor uniform elongation, due to early plastic instability. One of the possible ways to enhance ductility ofmaterials is to utilize deformation-induced martensitic transformation that leads to transformation-induced plasticity(TRIP). Metastable austenitic steels usually have low yielding strength and extremely high ductility because ofdeformation-induced martensite transformation. If the grain size of metastable austenite is refined into ultrafinegrained or nanocrystalline regime, both high strength and large ductility are expected. The present study preparednanocrystalline austenite with fully recrystallized morphology by severe plastic deformation and subsequent heattreatment, and investigated mechanical properties of the nanocrystalline austenite.