Phase Equilibria of Liquid Fe-S-C Ternary System

Abstract

Phase equilibria of Fe-S-C ternary melt has been studied to establish fundamental knowledge on the copper removal from iron melt by sulfide fluxes. Measurements were made to clarify the solubility of carbon and the miscibility gap between iron and FeS melts in Fe-S-C system at the temperature range from 1 473 to 1 873 K. Thermodynamic analysis was tried by applying interstitial solution model. Activity of iron in liquid Fe-C binary alloy was determined by distributing iron between liquid iron and silver phases to determine the interaction parameter between iron and carbon in Fe-C melt. It was concluded that interstitial solution model was applicable to express thermodynamic relation in this system. Phase diagram and activity contours of constituents in Fe-S-C ternary melt were calculated by the model. © 1991, The Iron and Steel Institute of Japan. All rights reserved.