Influence of Al content and precipitation state on the mechanical behavior of austenitic high-Mn low-density steels

We investigate the strain hardening of two austenitic high-Mn low density steels, namely, Fe-30.5Mn-2.1Al-1.2C and Fe-30.5Mn-8.0Al-1.2C (wt.%), containing different precipitation states. The strain hardening of the alloy with low Al content is attributed to dislocation and twin substructures. The precipitation of intergranular M3C-type carbides strongly influences the fracture mode. We associate the strain hardening behavior of the alloy with high Al content to the precipitation of shearable nanosized kappa-carbides and their role in the development of planar dislocation substructures. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.