Aline Lima da Silva

Aplicação da ferramenta termodinâmica computacional na simulação da produção de aço inoxidável

This work, done with the application of computational thermodynamics, deals with the fundamental aspects of the stainless steel production in the steelmaking. The understanding of the thermodynamics equilibria that occur during the process contribute for the improvement of operating controls and the yield of chromium - a comparatively expensive material. The methodology consisted to use the databases and the Gibbs Energy minimization routine of the FactSage software to calculate equilibria involving the systems Fe-Cr-O and Fe-Cr-O-C-Ni. The calculated values for the O content in equilibrium with Cr are in good accord with the obtained results using equations and data from literature. About the critical Cr concentration, at which the equilibrium oxide changes from FeO·Cr2O3 to Cr2O3, the results from this work are in good agreement with that values well known from literature, but show discrepancy when compared with recent works. Moreover, some aspects over which the technology is based are highlighted - the vacuum and temperature effects during refining process.