Work hardening behavior and fracture mechanisms of Fe-18Mn-1.3C-2Cr low-density steel castings with varying proportions of aluminum alloying

Abstract

The alloying of high-manganese steel with aluminum produces wear-resistant casting components with greater yield strength and significantly reduced density, which facilitates considerable energy-savings and service life extension in cement, mining, and construction operations. However, the strengthening mechanism of Al alloying responsible for the increasing yield strength, and how the fracture mechanism influences the work hardening behavior of these castings require further clarification. The present work addresses these issues by evaluating the work hardening behavior and fracture mechanisms of casting Fe–18Mn-1.3C–2Cr steels with Al alloying concentrations of 0, 4, 7, and 11 wt%. The results reveal that work hardening is facilitated by twinning-dislocation cell intersection in the absence of Al, by deformation band-planar slipping dislocation intersections et al. concentrations of 4 and 7 wt%, and by the precipitation of κ carbides at an Al concentration of 11 wt%. Furthermore, the tensile fracture mode increasingly varied from ductile fracture at 0 Al wt.% to brittle rupture at 11 Al wt.%, which was also accompanied by large voids and cleavages.