Effect of Chemical Components of Mould Flux on Dissolution Rate of Al_2O_3 into Molten Flux for High Manganese High Aluminum Steel

摘要

A mass of Al_2O_3 tends to form during the continuous casting process of high manganese high aluminum steel, and the properties of mould flux and the quality of slab are seriously affected. The dissolution rate of Al_2O_3 into the CaO-SiO_2-MgO-Al_2O_3-F~--Na_2O-Li_2O-BaO-B_2O_3 slag system has been investigated at 1573 K by employing rotating cylinder method. This paper focuses on the effect of Na_2O, Li_2O, B_2O_3, F~-, Al_2O_3 contents and (CaO+BaO)/(Al_2O_3+SiO_2) ratio on the dissolution rate. Experimental results show that the dissolution rate increases with increasing Na_2O, Li_2O, B_2O_3 contents and decreasing Al_2O_3 content, among which Li_2O has the greatest effect on increasing dissolution rate; the dissolution rate increases with increasing F~- content in slag A-1, but decreases with that in slag A-2; the dissolution rate increases with (CaO+BaO)/(Al_2O_3+SiO_2) ratio within the range from 0.91 to 1.31. The dissolution rate of Al_2O_3 into molten flux is mainly affected by the viscosity of the molten flux and the thermodynamic driving force.