neutron diffraction study of phase stress evolution in a ferrous medium-entropy alloy under low-temperature tensile loading

低温引張荷重下における鉄系中エントロピー合金の相変化の中性子回折によるその場観察

Bae, J. W.*; Kim, J. G.*; Park, J. M.*; Woo, W.*; Harjo, S.   ; Kim, H. S.*

Bae, J. W.*; Kim, J. G.*; Park, J. M.*; Woo, W.*; Harjo, S.; Kim, H. S.*

Phase stress evolution of face-centered cubic (FCC) and deformation-induced body-centered cubic (BCC) phases was measured in recently developed ferrous medium-entropy alloy. This was done during tensile deformation at -137C using neutron diffraction measurement for the quantitative interpretation of the role of martensitic transformation on the improved low-temperature tensile properties. The strain-hardening rate curve exhibits two-stage hardening behavior, and the phase stress and stress contribution from the BCC phase increases significantly while that from FCC phase decreases during plastic deformation. This is a direct demonstration that BCC phase contributes significantly to the increase in strength and strain hardening.