Experimental measurements and numerical analysis of al deoxidation equilibrium of molten Fe-Cr-Ni Alloy

The aluminum deoxidation equilibrium in molten Fe-10 to 40mass%Cr-8mass%Ni and Fe-18mass%Cr-8 to 30mass%Ni alloys was experimentally determined at 1 873 K and 1 773 K to obtain the thermodynamic parameters at both temperatures, corresponding to the refining and casting processes, respectively. Thermodynamic analysis on Al deoxidation was carried out based on the sub-regular solution model using a Redlich-Kister type polynomial. Fe-Al, Ni-Al, Cr-Al and Fe-Cr-Ni interaction parameters were obtained from experimental results and a thermodynamic assessment. Using these parameters, the Al deoxidation equilibrium over the complete composition range of the Fe-Ni alloy and in more than 50mass%Fe of the Fe-Cr and Fe-Cr-Ni alloys can be calculated for the temperature ranges of both of the refining and casting processes.