Dissolution behavior of alumina in mold fluxes for steel continuous casting

Abstract

Dissolution of alumina in various mold fluxes for steel continuous casting has been investigated by employing the rotating cylinder method. The weight loss of the rod, the dipping area and the immersed time were measured to determine dissolution rate of Al2O3. The dissolution rate increased with temperature of molten fluxes, the rotating speed of the rod and the addition of MgO, CaF2 and Na2O components in the mold flux. When the Na2O content exceeded 5%mass, the dissolution rate was found to decrease. Intermediate compounds such as CaO-6Al(2)O(3), CaO-2Al(2)O(3) and 2CaO-Al2O-SiO2 formed at the Al2O3/flux interface and formation of three compounds was found to play important roles in the dissolution rate. In conclusion, the dissolution of Al2O3 was controlled not only by the mass transfer in the molten flux but also by the formation of intermediate compounds on the interface.