Theoretical and experimental analyses of continuous casting with soft-contacted mould (II)--EMF calculation and experimental analyses

摘要

Coupling the quasi--3D numerical simulation of the electromagnetic field and the experiments with some met- als, a series of phenomena in the processes of continuous casting with soft-contacted mould was analyzed. Some theoretical and experimental models were presented, from which following results were obtained. 1) The electromagnetic force is re- lated with electric conductivity of billet as a power function to 0.4.2) The heat transfer between billet and mould is relat- ed with the contacting pressure, and it is a linear function for tin billet approximately. 3) The distance between initial so- lidification point and meniscus in billet is related with the surface magnetic flux density as a fourth root function. 4) The temperature gradient in the initial solidifying shell is reduced, which can decrease the tendency of hot tearing on the sur- face of billet, and increase the equiaxed crystal zone in billet. 5) The stronger the magnetic flux density is, the more shal- low and the thinner the oscillation mark on the surface of billet is. 6) The depth of oscillation mark on the billet cast by the soft--contacted mould can be reduced to about 10/100 in comparison with that on the billets cast by traditional mould. 7) In non-dimensional condition, the average depth of the oscillation marks on the billets cast by the soft-contacted mould decreases with increasing magnetic flux density on there as a complementary error function.