Grain boundary precipitation in Fe-30Mn-9Al-5Cr-0.7C alloy

Abstract

The as-quenched microstructure of the Fe-30%Mn-9%Al-5%Cr-0.7%C (in mass%) alloy was single-phase austenite. When the as-quenched alloy was aged at 550 degrees C-750 degrees C, fine (Fe,Mn)(3)AlC carbides were formed within the austenite matrix. In addition, as the aging temperature increased, a M7C3 carbide + D0(3) -> M7C3 carbide + B-2 -> M7C3 carbide + alpha (ferrite) phase transition had occurred on the grain boundaries. This grain boundary precipitation behavior has never before been observed in FeMnAlC and FeMnAlCrC alloy systems.