Gibbs Energies of Formation of TiS and Ti₄C₂S₂ in Austenite

Abstract

The Gibbs energies of formation of TiS and Ti₄C₂S₂ from Ti, S and C solutes in austenite are evaluated on the basis of the solubility data measured by Swisher in the Fe-C-S-Ti system. These quantities are employed in equilibrium calculations applied to a series of Ti bearing steels. The results indicate that Ti₄C₂S₂ is expected to predominate in Ti microalloyed steels, whereas both TiS and Ti₄C₂S₂ are likely to be present in Ti modified extra-low-carbon IF steels. These predictions are in good agreement with the experimental observations reported by other researchers.