A new austenitic FeMnAlCrC alloy with high-strength, high-ductility, and moderate corrosion resistance

Abstract

In this study, a new austenitic Fe-28%Mn-9%Al-6%Cr-1.8%C (in mass%) alloy is developed. Because the alloy contains a high density of fine (Fe, Mn) 3 AlC carbides within the austenite matrix, the alloy in the as-quenched condition exhibits an excellent combination of strength and ductility comparable to that of the aged FeMnAlC alloys. In addition, owing to the formation of a layer of Cr and Al oxides in the passive film formed on the alloys, the corrosion potential Ecorr (-538 mV) and the pitting potential Epp (-25 mV) of the present alloy in 3.5% NaCl solution are considerably higher than the Ecorr (-920∼-789 mV) and E pp (-500∼-240mV) values of the as-quenched and aged FeMnAlC alloys. Whereas the tensile strength of the present alloy is almost the same as that of conventional AISI410 martensitic stainless steel, the present alloy possesses superior ductility than AISI410 martensitic stainless steel. Furthermore, in 3.5% NaCl solution, the Epp (-25 mV) of the present alloy is noticeably higher than that (-250-100 mV) of the conventional AISI 410 martensitic stainless steel. These results indicate that the present alloy in the as-quenched condition can possess high-strength and high-ductility as well as moderate corrosion resistance. © 2010 The Japan Institute of Metals.