Interfacial tensions between CaO-SiO2-Al2O3 slag and Fe-O-S, Fe-Si, Fe-Al, Fe-C, Fe-Cr or Fe-Ni alloys

The interfacial tensions of 35mass%CaO-35mass%SiO2-30mass%Al2O3 slag with Fe-O-S, Fe-Si, Fe-Al, Fe-C, Fe-Cr or Fe-Ni alloys were investigated at 1580 degrees C by the sessile drop method. The interfacial tension for Fe-O-S system decreased with increasing oxygen and/or sulfur contents and their values (sigma) with oxygen and sulfur activities (a) were found to follow the relation, sigma(0)-sigma=0.3241n(1+116a(0)+8.5a(s)) ([S] <1mass%) In evaluating the effect of each alloying element on the interfacial tension, the difference in the oxygen content in each alloy was taken in the consideration. The interfacial tension was increased with increasing aluminum and silicon contents, slightly decreased with increasing carbon or nickel contents, and markedly decreased with increasing sulfur and chromium contents in the melt.