Effects of carbon and oxygen on Fe-C-O melt surface tension

Abstract

For this study, we measured surface tension of Fe-C and Fe-C-O melts accurately under controlled carbon and oxygen activities using an oscillating droplet method with an electromagnetic levitator (EML). The results are summarized as follows. The carbon activity has no influence on the surface tension of Fe-C melt at temperatures of 1 823-2 023 K under oxygen partial pressure of 10-10 Pa. For Fe-C-O melts, the carbon activity has no influence on the surface tension at a constant oxygen partial pressure of 10-7 Pa and temperatures of 1 873-1 973 K. It is noteworthy that oxygen activity is reduced by carbon in the melt because of the negative interaction between oxygen and carbon. Considering the interaction, the surface tension of the Fe-C-O melts was formulated as a function of carbon and oxygen concentrations and temperature. © 2013 ISIJ.