OXYGEN ACTIVITY AND SOLUBILITY BEHAVIOR ON COOLING AND SOLIDIFICATIONOF FE-C-SI-O MELTS

The equilibrium states in Fe-C-Si-O system melts (0.15% C) were subjec ted to computer-aided analysis. Given the competing carbon and silicon oxidation reactions, conditions are established at some temperature p oints of the cooling curve and in the solidification interval for a te rnary equilibrium in a supercooled melt. At temperatures below these p oints inversion of the chemical interaction occurs (one reaction super sedes another). in any case, as soon as solidification begins the oxid ation of the reagents is strongly accelerated owing to the differentia tion of the composition in the crystals - liquid - oldde phase system. The features established in this study exert a strong effect on the f inal equilibrium state and composition of reaction products. Solidific ation maintains its role of the leading process.