Influence of basicity of mold flux on its crystallization rate

Abstract

Crystallization of mold flux was observed with confocal laser microscope. Crystallization temperature, CCT curve and crystallization rate were evaluated from the observed images. The evaluated results were compared between two kinds of mold flux, and influence of basicity on crystallization rate was discussed. Crystallization temperature increased with basicity. Crystallization rate also increased with basicity, but its dependency on cooling rate was differed by basicity. The difference could be explained by the viscosity of mold flux at crystallization temperature. Crystallization rate has clear relation to the viscosity at crystallization temperature, and the rate increased with decrease of the viscosity. Two kinds of mold flux were unified in this relationship. Crystallization is controlled with basicity in terms of not only equilibrium but also kinetics through viscosity. © 2013 ISIJ.