Decoding the Deformation Behavior of High Mn Steel Following the Profilometry-Based Indentation Plastometry (PIP) Tests

Abstract

The newer generation high-Mn steels have gained considerable attention in the automotive, construction, and mining sectors owing to their enhanced strength combined with a reasonable amount of ductility. In the present work, these Fe-Mn-C steels undergo heat treatment (HT) at temperatures ranging between 300°C and 500°C, which monitors the microstructure and the resulting mechanical properties of the developed material. The formation of carbides with the increasing temperature plays an important role in altering the mechanical properties, notably the enhanced strength and hardness of the 500˚C-HT specimen, following the profilometry-based indentation plastometry (PIP) test. However, the localized presence of these carbides serves as the potential site for the initiation of cracks, compromising the overall properties. Further, the emergence of deformation bands nearby to the indentation was clearly noticed during the PIP test. Post-EBSD characterization revealed an intense strain localization within evolving deformation bands, leading to a continuous decrease in uniform strain and a corresponding increase in the tensile strength of 500˚C-HT specimen. TEM analysis discloses the complex arrangement of dislocations within the deformation bands that are responsible for inducing strain and distorting the crystal lattice. Finally, these microstructural features contribute to a lower specific wear rate and reduced wear volume, justifying the superior wear resistance behavior and higher strength of the above-mentioned specimen.