Microstructure and Plasticity Evolution During Lüders Deformation in an Fe-5Mn-0.1C Medium-Mn Steel

Abstract

The local plasticity and associated microstructure evolution in Fe-5Mn-0.1C medium-Mn steel (wt.%) were investigated in this study. Specifically, the micro-deformation mechanism during Lüders banding was characterized based on multi-scale electron backscatter diffraction measurements and electron channeling contrast imaging. Similar to other medium-Mn steels, the Fe-5Mn-0.1C steel showed discontinuous macroscopic deformation, preferential plastic deformation in austenite, and deformation-induced martensitic transformation during Lüders deformation. Hexagonal close-packed martensite was also observed as an intermediate phase. Furthermore, an in-situ neutron diffraction experiment revealed that the pre-existing body-centered cubic phase, which was mainly ferrite, was a minor deformation path, although ferrite was the major constituent phase.