Thermodynamic Assessment of Steelmaking Practices for the Production of Re-sulfur Steels

Abstract

FactSage has become one of the most important modeling tools in simulating the high-temperature metallurgical processes. The usefulness of the FactSage has been demonstrated in this work using several examples of steelmaking processes. Primary steelmaking (basic oxygen furnace) simulation was done with the available process data, and process charts similar to the standard ones were obtained. Ladle refining furnace process for free-cutting steels was simulated and it was observed that absolute non-equilibrium condition exists in steel during casting due to S injection. It was found that non-metallic inclusion formation is thermodynamically possible at final processing stages during Ca and S injection with variable recoveries. A significant change in the nature of non-metallic inclusions formed in re-sulfur steel causes clogging during continuous casting of liquid steel, and its influence on the process has been discussed, for mere 2 ppm of Ca difference in the liquid steel composition.