Enhanced Mechanical Properties of Fe-Mn-Al-C Low Density Steel via Aging Treatment

Abstract

This study investigated the tensile properties and deformation behavior of an aged Fe-26Mn-6Al-1C (mass%) alloy with a stacking fault energy of approximately 60 mJ·m −2 . The results show that an ordered phase with a “short-range ordering” (SRO) structure formed after aging at 550°C for 10 h, further increasing the aging time to 48 h. Lamellar second-phase precipitates appeared at the austenitic grain boundaries. The aged sample at 550°C for 10 h exhibited an enhanced tensile strength (∼898 MPa) without notably sacrificing uniform elongation (∼46.3%), which was mainly attributed to the relatively high strain hardening in the entire plastic deformation due to the synergistic effects of planar slip, twinning-induced plasticity (TWIP), microband-induced plasticity (MBIP), and especially the formation of short-range ordering.