ELECTROMAGNETIC STIRRING METHOD OF UNSOLIDIFIED MOLTEN STEEL IN CRATER END IN CONTINUOUS CASTING OF BLOOM

摘要

PURPOSE:To prevent effectively the central segregation and center cavity of an ingot and to improve quality by forcing spiral flow in molten steel by means of a composite stirrer combined with electromagnetic coils of a linear motor type and a rotary motor type. CONSTITUTION:Spiral flow 12 directing toward a crater end 4 of a bloom 4 formed by drawing the molten steel 1 in a casting mold 2 continuously with roll aprons 3 is induced in the narrow unsolidified molten steel 1b enclosed by a thick solidified shell 1a near said creater end by using a composite stirrer 11 combined with a rotary motor type electromagnetic coil 10 which turns and flows the molten steel around the axial center at the center of said steel in the drawing direction for casting and a linear motor type electromagnetic coil 9 which propels the molten steel axially along the axial center. Additional one set of said stirrer 11 may be installed along the drawing direction for casting or the coil 9 may be combined on the down stream side of the coil 10.