Study on electromagnetic control method of high-speed continuous casting technology integrating multiphase and multifield simulation and multi-objective evaluation

Purpose The purpose of this study is to address the instability of meniscus behavior and the difficulty of matching optimal electromagnetic braking (EMBr) parameters under high-speed continuous casting conditions. A novel decision-based EMBr control method is proposed to achieve stable meniscus behavior and improved initial shell quality in slab continuous casting. Design/methodology/approach A transient three-dimensional multiphase and multiphysics coupling model of the mold (MPF-Mold) is developed to analyze the effects of casting speed and double-ruler EMBr (FC-Mold) parameters on molten steel flow and meniscus behavior. Eight evaluation indicators are extracted, and a combined principal component analysis-technique for order preference by similarity to ideal solution (PCA-TOPSIS) approach is used for weight assignment and multi-objective optimization. Findings The results indicate that the uniformity index of initial shell thickness U(Thick shell) has the highest weight (0.451), followed by maximum meniscus velocity and level fluctuation amplitude. The optimal EMBr condition (lower field 0.33T, upper field two-thirds of the lower) reduces meniscus velocity from 0.52 m/s to 0.34 m/s, limits level fluctuation to ± 2 mm, increases initial shell thickness by 0.5 mm and improves U(Thick shell) from 0.842 to 0.895. Originality/value This study integrates numerical simulation with decision analysis for the first time to establish a rapid matching method of EMBr parameters for meniscus control. The developed PCA-TOPSIS-based optimization framework provides a practical and efficient strategy for stabilizing the meniscus and enhancing slab surface quality in high-speed continuous casting.