Influence of Al and C on Mechanical Properties of Sub-Rapidly Solidified Fe-20Mn-xAl-yC Low-Density Steels

Abstract

Fe-Mn-Al-C low density steels with high manganese and high aluminum content have received much attention recently because their potential of more than 10wt.% reduction of density, excellent mechanical properties and multiphase microstructures. For present study, sub-rapidly solidified Fe-20Mn-xAl-yC low-density steels with different Al (5, 9,12wt.%) and C(0.4, 0.6, 0.8, 1.0,wt.%) have been produced to understand the influence of Al and C on phases content and mechanical properties. These near-net shaped Fe-20Mn-xA-yC steels all revealed duplex phases (δ+γ) during sub-rapid solidification, and some ordered DO3 phases formed in -ferrite. The changes of aluminum and carbon content lead to the volume fractions changes of -ferrite, and the dissolved aluminum content have a vital influence on tensile properties, but there is no clear relationship between phase proportions and tensile properties. The yield strength, ultimate tensile strength and total elongation of 9Al-0.8C steel are 593MPa, 952 MPa, and 46%, respectively, which shows the best comprehensive performance of these sub-rapidly solidified Fe-20Mn-xA-yC steels.