Abstract: This study focuses on the effective control of inclusions in molten steel during the continuous casting of silicon steel through the optimization of tundish covering flux. Using FactSage thermodynamic software, simulations were conducted to analyze the variations in liquid slag and inclusion content under different types, ratios, and compositions of tundish covering flux, as well as their effects on oxygen and aluminum levels in the steel. The computational results demonstrate that compared to the FG-13 type, the application of FG-5 tundish covering flux increases the liquid slag content by 0.083 4 g per 100 g of steel while reducing oxide inclusions by 0.060 57 g per 100 g of steel. At the ratio of covering flux to steel is 1∶100, the average liquid phase area is 0.16 percentage points higher than that at 1.5∶100 and 0.58 percentage points higher than at 2∶100, indicating improved slag fluidity and enhanced impurity absorption capacity. Industrial trials validated the optimized formulation, showing a significant reduction of 10.9 percentage points in Al-containing inclusions in steel samples.

Key words: continuous casting, tundish covering flux, thermodynamics, silicon steel, inclusions