The Role of Molybdenum on Room Temperature Tensile Behavior of Recrystallized Fe30Mn5Al1CxMo Lightweight Austenitic Steels

The present study investigated the room temperature tensile behavior of recrystallized Fe30Mn5Al1C (0–3) wt% Mo alloys. The 0-Mo and 0.5-Mo alloys have a single-phase austenitic structure, while 2-Mo and 3-Mo alloys have molybdenum-enriched carbides embedded in an austenitic matrix. Adding Mo up to 3 wt% increased the yield strength by ~ 36% and ultimate tensile strength by ~ 18%, but decreased fracture strain by ~ 52%. The increase in yield strength is attributed to solid solution as well as precipitation strengthening, while the drop in fracture strain to the early crack nucleation of interphase debonding between matrix and carbides in the 3-Mo alloy. The underlying strengthening contributions to the YS in each alloy were calculated and discussed in detail.