Influence of Grain Size on Work-Hardening Behavior of Fe-24Ni-0.3C Metastable Austenitic Steel

摘要

In this study, the effect of grain size on the work-hardening behavior of Fe-24Ni-0.3C metastable austenitic steel was investigated by the use of in situ neutron diffraction during tensile tests in Japan Proton Accelerator Research Complex (J-PARC). The effect of grain size on the work-hardening behavior was considered from viewpoints of martensite formation and stress partitioning between different phases. The result revealed that when the grain size changed within the coarse grained region the influence of the grain size on the stress partitioning was relatively small, thus the work-hardening behavior was mainly determined by the increasing rate of martensite volume fraction. On the other hand, when the grain size decreased down to ultrafine grained scale, the internal stress (phase stress) in martensite significantly increased, which contributed to the increasing work-hardening rate.