A coupled model including electromagnetic field, fluid dynamic, heat transfer and so-lidification, is developed and applied to the numerical simulation of steel flow andsolidification in a 100mm× 100mm soft-contact mold. In this study, the 3D finite dif-ference method and n, on-staggered grid system for fluid flow with body fitted coordinatewere employed. Numerical results show that the electromagnetic force mainly affectsthe steel flow at upper part of mold, especially in the vicinity of meniscus. There existupward flows covering the surfaces of the billet due to the concentration of electro-magnetic force on the upper part of the billet. This flows join together and form adownward flow near the SEN, so a distinct circulating flow zone is formed at upperpart of mold. After applying electromagnetic force, the steel velocity is improved andthe temperature is raised. The strong stirring of electromagnetic force on liquid steelmakes the kinetic energy on free surface increase. It is clearly seen that the solidifi-cation start point shifts downward in soft contact mold. As a result, the initial shellthickness gets thin and the initial solidification shell length is shortened.
A.Y. Deng and J.C. HeKey Laboratory for Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110004, China
The three-dimensional electromagnetic characteristics and non-uniform distribution of electromagnetic field in soft-contact mold have been analyzed by numerical simulation. The results show that the maximum electromagnetic flux density is found in front of slit; the electromagnetic flux density becomes large as coil current and slit number increase. In a certain frequency range, the electromagnetic flux density increases with increasing frequency; and the frequency range is different with changing of azimuthal position along inner wall of mold. The uniformity of electromagnetic field is effected mainly by frequency and mold structure parameters. Increasing slit number and adjusting slit arrangement position can improve the electromagnetic flux density and the uniformity of electromagnetic field. For a soft-contact mold with 16 slits, when frequency is 20kHz, the optimal slit arrangement parameter is a: b = 1: 2, c = 0.
A. Y. Deng, G.L. Jia and J.C. He (Key Laboratory for Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110004, China)
