CONTINUOUS CASTING METHOD FOR LOW CARBON STEEL, USING IMMERSION NOZZLE WITH PIT-TYPE RESERVOIR

摘要

PROBLEM TO BE SOLVED: To provide a continuous casting method for low carbon steel, by which the drift in the thickness direction of a mold is reduced, while the degree of solidification delay is improved, and a cast slab with an excellent surface quality is obtained.;SOLUTION: The shapes of discharging ports 2, 2 of an immersion nozzle 100 used for continuous casting are appropriately determined. For example, in a longitudinal cross section of the immersion nozzle 100, an angle θ4 between the hole-bored direction of the discharging ports 2, 2 and a surface Src perpendicular to the axis of the immersion nozzle 100 is set within a predetermined range, and the aperture areas of the discharging ports 2, 2 are set within a predetermined range. A mold, whose width and thickness at its upper end are appropriately set, is used. A casting velocity Vc [m/min] is set to be 1.0-2.4, and the degree of superheat ΔT [°C] is set to be 20-45. Further, while electromagnetically stirring the molten steel poured into the mold at an in-mold electromagnetic stirring intensity M-EMS [gauss] of 0-1,200, the molten steel is continuously cast.;COPYRIGHT: (C)2008,JPO&INPIT