JPS5597855A - Electromagnetic stirring method - Google Patents

Abstract

PURPOSE:To effectively prevent the bridge formation during the progression of solidification by selecting the magnetic field system to be acted upon the casting slab in correspondence to the thickness and cross sectional shape of the casting slab at the time of electromagnetically stirring unsolidified molten steel in the process of continuous casting. CONSTITUTION:In the system of generating dynamic magnetic fields such as revolving magnetic fields or linear magnetic fields upon the casting slab and generating electromagnetic force through mutual action with the induction current induced in the casting slab, the penetration depth of the induction current of the case where commercial frequencies are used is 100mm or less and therefore the electromagnetically stirrable slab thickness becomes 80-200mm, thus the static electromagnetic system is more advantageous for the slab of 200-500mm in thickness. Further with the flattening ratio (long side/short side) of the slab cross section being 1.0-1.8, the revolving magnetic force Hi in contact with the long side and the revolving magnetic force H0 in contact with the short side balance and therefore the revolving magnetic field system is more advantageous, but in the case of the flattening ratio being 1.8-2.2, the linear magnetic field system is more advantageous.