Numerical Simulation of Melt Flow, Heat Transfer and Solidification in Final Solidification Zone of Bloom Continuous Casting with Vertical Linear Electromagnetic Stirring

In this study, a novel technique of Vertical Linear Electromagnetic Stirring (V-LEMS) was proposed and applied in the final solidification zone of the 260 mm × 300 mm GCr15 bearing steel continuous casting (CC) bloom. The effects of V-LEMS on melt flow, heat transfer, and solidification have been investigated by establishing a three-dimensional numerical simulation model. The results demonstrate that an effective longitudinal magnetic field is formed in the inner arc of the bloom by applying V-LEMS, which is 1.9 times the height of the V-LEMS device, and the electromagnetic force within this effective longitudinal magnetic field is greater than 1.0×103N·m-3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1.0 \times 10^{3} {\text{ N}}{ \cdot }{\text{m}}^{{ - 3}}$$\end{document}. The V-LEMS induces longitudinal circulation flow in the liquid core of the bloom, whose height reaches 1.8 times of the V-LEMS device, so as to promote longitudinal mixing of the melt. The longitudinal circulation flow transports the high-temperature melt in the upper region of the liquid core to the lower region of the bloom, which improves the temperature uniformity of the liquid core, and it is beneficial to increase the proportion of equiaxed grains in the center of the bloom. By applying V-LEMS in the final solidification zone of the bloom, the melt temperature near the solidification front in the liquid core is 6.5 K higher than that without V-LEMS, and the width of the liquid core is 4.3 mm wider than that without V-LEMS. These effects are beneficial to improve the fluidity and feeding ability of the melt in the liquid core and reduce defects such as porosity, shrinkage cavity, and cracks in the center of the bloom.