750MPa grade ultrahigh-strength Fe-Mn-Al-C series light cast steel and preparation method thereof

The invention provides 750MPa grade ultrahigh-strength Fe-Mn-Al-C series light cast steel and a preparation method of the 750MPa grade ultrahigh-strength Fe-Mn-Al-C series light cast steel. Accordingto the chemical components of the light cast steel, the 750MPa grade ultrahigh-strength Fe-Mn-Al-C series light cast steel comprises, by weight percentage, 0.60%-1.50% of C, 10.00%-14.00% of Mn, 6.50%-12.00% of Al, 0.50%-1.50% of Si, 0.15%-0.55% of Ni, 0.15%-0.45% of Cr, 0.01%-0.06% of Cu, 0.10%-0.60% of Mo, 0.05%-0.25% of V, 0.05%-0.35% of Ti, 0.01%-0.08% of Nb, 0.001%-0.010% of Ce, smaller thanor equal to 0.008% of P, smaller than or equal to 0.008% of S and the balance Fe and inevitable impurities. The 750MPa grade ultrahigh-strength Fe-Mn-Al-C series light cast steel achieves the cooperation of the quite high strength, the quite high density and the quite high plasticity, is quite suitable for manufacturing automotive complex structure castings and can effectively reduce the dead weight of an automobile. 本发明为种