Abstract: The effects of Cr and Al content were investigated on the stacking fault energy in austenitic Fe-31Mn-(0-7.26)Cr-0.96C and Fe-31Mn-(0-8.68)Al-0.85C alloys by the thermodynamic analysis.The results show that the additions of chromium or aluminum increase the non-magnetic component of the stacking fault energy in the γ-Fe-Mn alloys,and the effect of aluminum is larger than that of chromium.The change in the magnetic entropy caused in the antiferromagnetic transition increases the free energy difference between the γ and ε phases in the γ-Fe-Mn alloys.The effects of chromium and aluminum on the magnetic component were discussed on the basis of the influence of both upon the antiferromagnetic transition in the γ-Fe-Mn alloys.

Key words: stacking fault energy, thermodynamics, antiferromagnetic transition,