USE OF THERMODYNAMICS FOR IMPROVING STEEL ELABORATION

The optimization of high temperature reactions faking place during ste el elaboration is improved with a precise evaluation of thermodynamic relationships. Reactions of interest include gas-metal reactions (dega ssing and metal grading, gaseous emissions during the melting of scrap , ...), reactions between metal, various slags (blast furnace, refinin g, ladle metallurgy) and refractory linings, formation of oxide inclus ions and various precipitates (sulphides, nitrides, carbides,...) in l iquid or solid metal. The type of thermodynamic information needed com prises phases diagrams and component activities in multicomponent syst ems, as well as properties of various compounds. A rational use of thi s thermodynamic information is only possible with reliable solution mo dels and efficient multiphase equilibrium calculation codes. This pape r presents a description of such models in use or under development at Irsid, and of the thermodynamic multiphase equilibrium code CEQCSI. T wo examples show the practical use of these tools.