Kinetics of nonisothermal crystallization of SiO ₂ –TiO ₂ –CaO–BaO–Al ₂ O ₃ ‐based fluorine‐free mold flux for high‐Ti steel

Abstract This study investigated the nonisothermal crystallization kinetics behavior of SiO 2 –TiO 2 –CaO–BaO–Al 2 O 3 ‐based fluorine‐free mold fluxes during high‐Ti steel continuous casting. By analyzing the thermodynamic characteristics of crystallization and characterizing the precipitated crystalline phases, this study examined the influence of three key component ratios—CaO/SiO 2 (0.95–1.25), CaO/BaO (1.00–3.00), and SiO 2 /TiO 2 (2.40–5.20)—on the crystallization mechanism, crystal growth mode, and precipitated phases of the mold flux under heating conditions. The results indicate that the nonisothermal crystallization kinetics involves a complex mechanism exhibiting dynamic evolution. High CaO/SiO 2 ratios resulted in elevated crystallization rates, whereas high CaO/BaO ratios accelerated crystal growth. High SiO 2 /TiO 2 ratios increased the degree of depolymerization of the network structure, inhibiting three‐dimensional crystal growth. Furthermore, BaAl 2 Si 2 O 8 and CaTiO 3 crystalline phases primarily precipitated under medium temperatures (800–900°C), whereas CaTiO 3 and Ca 2 Al 2 SiO 7 were predominant under high temperatures (1000–1100°C). Different from previous studies focusing on single oxides, this work provides full‐scale insights into the synergistic effects of multiple component ratios on nonisothermal crystallization behavior, offering both mechanistic understanding and practical guidance for optimizing fluorine‐free mold fluxes in high‐Ti steel continuous casting.