PURPOSE: To prevent the generation of reverse V segregation and porosity on account of the defective contact between a casting mold for casting a steel ingot for an extra thick plate material and the casting ingot by constituting said mold of long-side casting molds having an upward divergent taper and short side casting molds moving vertically in inscribing said molds.
CONSTITUTION: A casting mold 1 for a steel ingot for an extra thick plate material is constituted of long-side casting molds 2 diverging upward and short side casting molds 4 having water-cooled copper plates 6B sandwiched between water-cooled copper plates 6A provided on the inside thereof. The molds 4 are made vertically movable along guide posts 10 and pressing devices 8 are provided to the molds 2. A molten steel 16 is charged from a charging pipe 18 through a runner 20 into the mold 1 from the bottom thereof. When a clearance is produced between the plates 6A of the long-side molds upon formation of a solidified shell 16A, the cooling rate thereafter decreases and therefore the molds 2 are slightly opened by the devices 8 and after the molds 4 are slightly moved upward by moving devices 12, the molds 2 are again pressed to the shell 16A of the casting ingot by the devices 2, thereby accelerating the cooling. The above-mentioned operation is repeated plural times to cool and solidify smoothly the casting ingot in the mold 1.
EMOTO KANJI
MATSUKAWA TOSHITANE
