Melt flow, heat transfer and solidification in bloom continuous casting with combined vertical linear electromagnetic stirring and rotary electromagnetic stirring

An opposite combined vertical linear electromagnetic stirring (CV-LEMS) was proposed, which is applied in the final solidification zone of bloom continuous casting. The melt flow, heat transfer, and solidification under CV-LEMS were investigated by establishing a three-dimensional numerical simulation model and a pilot continuous casting simulation experiment and compared with the conventional rotary electromagnetic stirring (REMS). The results show that a longitudinally symmetric linear magnetic field is formed in the liquid core of the bloom by applying CV-LEMS, which induces a strong longitudinal circulation flow both on the inner arc side and the outer arc side in the liquid core of the bloom. The height of the melt longitudinal effective mixing range under CV-LEMS reaches 0.9 m, which is greater than that of the REMS and makes up for the deficiency of REMS sensitivity to the position of the final solidification zone. CV-LEMS strongly promotes the mixing of upper melt with high temperature and the lower part melt with low temperature in the liquid core, improves the uniformity of melt temperature distribution and significantly increases the melt temperature near the solidification front, and the width of the liquid core increases by 4.2 mm at maximum. This shows that the appliction of CV-LEMS is more helpful to strengthen the feeding effect of the upper melt to the solidification shrinkage of the lower melt than the conventional REMS and inhibits the formation of porosity, shrinkage cavity and crack defects in the center of the bloom.