Structural and Rheological Study for Silicon Carbide Influence on Shear Thinning Behavior of CaO-SiO2-CaF2 Based Mold Flux

Abstract

In continuous steel casting process, calcium silicate glass melts referred as mold flux is used for improving steel quality. This glass melts need to show shear thinning property considering that main functions of mold flux are preventing entrapment of molten mold flux into molten steel on the mold top surface and lubrication between mold wall and steel shell. In order to control shear thinning property, the author incorporated silicon carbide into silicate structure of mold flux by using electric arc furnace which can generate high temperature in a short time. With this prepared sample, viscosity measurement by rotational viscometer for observing shear thinning degree of the sample and structural analysis by Raman spectroscopy for measuring degree of polymerization were conducted. Through these results, the author found that a small amount of silicon carbide could improve shear thinning property by increasing degree of polymerization. Furthermore, it was also founded that silicon carbide could have the strongest shear thinning property. The degree of shear thinning property for silicon oxy-carbide glass were quantified by Oswals-De Waele power law model.