Relationship between Microstructures and Tensile Properties of an Fe-30Mn-8.5Al-2.0C Alloy

Abstract

Owing to the presence of a large amount of fine (Fe,Mn)(3)AlC carbides within austenite (gamma) matrix, the tensile property of the Fe-30%Mn-85Al%-20%C (in mass%) alloy in the as-quenched condition was clearly superior to that of the as-quenched FeMnAlC (C <= 1 3%) alloys investigated by previous workers After being aged at 823 K for 3 h, the present alloy could possess high yield strength up to 1262 MPa with an excellent 32 5% elongation With almost equivalent ductility. the yield strength obtained was about 16% higher than that of the FeMnAlC (C <= 1 3%) alloys after solution heat-treatment or controlled-rolling followed by an optimal aging at 823 K Additionally, due to the pre-existing fine (Fe,Mn)(3)AlC carbides within the gamma matrix in the as-quenched alloy, the aging time required for attaining the optimal combination of strength and ductility was much less than that of the FeMnAlC (C <= 1 3%) alloys aged at 823 K When the present alloy was aged at 823 K for a time period longer than 4 h. both the strength and ductility were drastically dropped due to the occurrence of gamma(0)/kappa (gamma(0) carbon-deficient austenite) lamellar structure on the gamma/gamma gram boundaries [doi 10.2320/matertrans.M2010013]