Phase equilibria and thermal analysis in the Fe–Mn–Ni system

Abstract

Abstract Based on the critical review of the experimental data available in the literature, 7 decisive ternary alloys were prepared. New phase transition temperatures and phase equilibria at 800°C in the Fe – Mn – Ni system were measured. An effective method to accurately determine phase transition temperatures from differential thermal analysis curves with overlapped peaks and nonlevel baselines within a narrow temperature range was developed. A massive transformation was observed in one quenched Fe-rich alloy. In order to make the fcc_A1 phase always in the fully disordered state in the ternary system, the effect of the binary reciprocal parameter on the Gibbs energy of ternary ordered L12 phase was considered. It was found that the introduction of only one parameter could describe all reliable experimental data in the Fe – Mn – Ni system satisfactorily. The presently obtained parameters were successfully applied in two practical cases.