Evidence supporting reversible martensitic transformation under cyclic loading on Fe-Mn-Si-Al alloys using neutron diffraction

澤口 孝宏*; 友田 陽*; 吉中 奎貴*; Harjo, S.

Acta Materialia, 242, p.118494_1 - 118494_14, 2023/01

https://doi.org/10.1016/j.actamat.2022.118494

Fe-Mn-Si-based alloys, show superior resistance to plastic fatigue compared to the conventional steels, which is ascribed to the reversible back-and-forth movement of Shockley partial dislocations associated with a reversible martensitic transformation between the face-centered cubic -austenite and hexagonal close-packed -martensite. The purpose of this study was to gather evidence of the reversible martensitic transformation using in situ neutron diffraction under cyclic loading. Three Fe-30Mn-Si-Al alloys with different Gibbs free energy differences at 298 K were studied to unravel the effect of phase stability on the degree of reversibility.