The density

solidification and cooling path

phase transformation and precipitates phase of Fe-( 5 ~ 15 ) Mn-( 6 ~ 12)Al-( 0. 5 ~ 1. 0 )C low density steel are studied by FactSage and JMatPro numerical simulation software. The vertical sections of phase diagram of this system is calculated by using the FSstel database of FactSage software. Based on these vertical sections

the influence of Mn

Al and C is analyzed in the phase transformations and precipitates phase during solidification and cooling to get a diagram of the equilibrium phase-transformation path of Fe-12Mn-8. 5A1-0. 8C low density steel. The results indicate that the full-phase transformation path of Fe-12Mn-8. 5Al

-0. 8C low density steel during the cooling process from 1 600 °C to 600 °C is Liquid → Liquid + Ferrite → Liquid + Ferrite + Austenite → Ferrite + Austenite → Austenite → Austenite + κ-carbide Ferrite + Austenite + κ-carbide. With the increase of C and Mn contents ， the austenite phase zone can be enlarged and the austenite can be stabilized. With the increase of Al contents

the austenite phase zone can be reduced and the ferrite can be stabilized. The precipitation temperature of K-carbide increases with the increase of Al and C content

and Al and C can promote the precipitation of carbides K-carbide precipitation. The density of Fe-12Mn- 8. 5Al-0e 8C low density steel calculated by JMatPro is 7. 05 g/cm

3

and the density of steel measured by experiment is 7. 00 g/cm

3

.