Mixing effect of slag compositions and additives on crystallization of mold fluxes for Ti-bearing steels

Abstract

Increasing titanium content enhances the high temperature corrosion resistance and strength of steel and alloy, whereas it is prone to induce the severe slag/metal reaction during continuous casting, causing great property change of mold flux. With the aim of understanding their influence rule to further control perovskite precipitation for industrial application, in this paper, the mixing effect of TiO2, basicity and additives including BaO, B2O3 and Li2O on the crystallization characteristic of mold flux has been investigated through combined analysis of DSC, XRD and SEM-EDS. The results indicated that increase of TiO2 from 0 consecutively decreased crystallization temperature and crystal size of cuspidine but accelerated initial precipitation and crystallization temperature and size of perovskite since 8% TiO2. Increase of basicity in the case of 12% TiO2 enhanced the overall crystallization capacity regarding crystallization temperature and size of cuspidine and perovskite. Under moderate basicity and high TiO2 content, B2O3 has strongest suppression effect on mold flux crystallization, BaO has decreasing suppression effect and Li2O has weakest suppression effect compared with them. For different TiO2 pickup and basicity of mold flux, varying strategies were suggested to adjust the crystallization considering the mixing effect of mold flux compositions and additives.