An accelerated aging assisted by electric current in a Fe-Mn-Al-C low-density steel

An aging method assisted by electric current was applied to a Fe-18Mn-9Al-1C (wt.%) low-density steel.It improves the microstructure and therefore significantly increases both the yield strength and ductility of the steel.This current-assisted aging method can increase the yield strength by 178 MPa and elongation by 1.16 times in only 0.5 min at 450 °C.However,the yield strength is increased only 90 MPa by the traditional aging method (heat conduction) at 450 °C for 180 min,and the elongation is even decreased from 42.0% to 31.6%.The obvious improvement in yield strength by the current-assisted aging for a short time is resulted from the fact that the current-assisted aging promotes a rapid precipitation of nano-scale κ-carbides in γ-austenite by reducing the thermodynamic barrier and accelerating the atomic diffusion.This work demonstrates that this current-assisted aging method is significantly time saving and cost-effective for low-density steels,with potential for various industrial applications.