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 degrees C. However, the yield strength is increased only 90 MPa by the traditional aging method (heat conduction) at 450 degrees 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 k-carbides in gamma-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.

Automated summary

The study demonstrates that an electric current assisted aging method can significantly increase the yield strength and ductility of low-density steel. Compared to traditional aging methods, this current-assisted aging method achieves better results in a shorter time period, mainly due to the promotion of rapid precipitation of nano-scale carbides.