9th ECCC European Continuous Casting Conference – ECCC 2017

High Al steel containing Al more than a percent has been recently developed which increases specific strength significantly by forming very fine FeAl intermetallic compounds in the matrix. For a successful commercial production, continuous casting is prerequisite, but the high Al content causes serious trouble for the casting practice due to strong reaction between Al and SiO2 in mold flux. In order to find countermeasures against degradation of mold flux properties, it is important to understand the chemical reaction between the steel and molten mold flux. The present paper demonstrates the authors’ laboratory scale experimental result showing reaction mechanism between the high Al steel and the CaO-SiO2 based mold flux. Based on those observed mechanism, a slag-metal reaction model was developed in order to interpret the reaction and to predict similar reactions between high Al steel and mold flux used for continuous casting process. The model considers thermodynamic/kinetic information, and the rate-controlling steps observed in the authors’ investigation. Thermodynamic information was obtained by ChemApp and FactSage thermodynamic database. This is connected to mass flux equations for all relevant components in the system. Varying viscosity of the flux and its effect on the mass flux are also considered. The reaction model showed good accordance with of the experimental data. Some possible applications are also shown.