Effects of Ni Content on Reversible Deformation-Induced Martensitic Transformation of Fe–Mn–Cr–Si–Ni Alloy Under Uniaxial Deformation

Abstract

The effects of Ni on the reversible deformation-induced martensitic transformation of Fe–20Mn–11Cr–4Si–xNi (x = 2, 4, 6 wt pct) alloys and the corresponding deformation mechanism under uniaxial deformation were studied. As the Ni content increased, the amount of strain-induced and athermal ε-martensite decreased because the Ni addition increased the thermal stability and stacking fault energy (SFE). In contrast, the deformation-induced reverse transformation ε → γ sharply increased. TEM and EBSD analyses showed that Shockley partial dislocations remained at the same slip plane for the reversible martensitic transformation (γ ↔ ε). Thus, SF intersection and athermal ε-martensite acted as a barrier against dislocation movement in reverse martensite phase transformation (ε → γ). This suggests that the Ni content should be optimized to balance the forward and reverse phase transformation under plastic deformation.