PURPOSE: To perform blooming which prevents the production of laps occuring in metal penetration flaws in blooms by preventing the penetration of molten metal between the inside wall surface of the mold and a disconnected sleeve owing to metal penetration by means of a cushion member at the time of ingot making.
CONSTITUTION: A cushion material 3 molded by material such as asbestos or slag wool is bonded and fixed to the bottom edge part 2 of a heat-insulation sleeve 1. The sleeve 1 is then installed to the inside wall surface 5 in the upper part of a mold 4 by way of the cushion material 3 to form a head part 6, after which molten steel a is poured to make a killed steel ingot. As a result, the fittness by the chshion material 3 to the undulated surface of the inside wall surface of the mold 4 in its position is given to the sleeve 1 thereby giving tight installation. Hence, the penetration of the molten steel a between the surface 5 and sleeve 1 owing to metal penetration at the surface 5 may be prevented and the formation of metal penetration flaws may be eliminated.
YAMANAKA SUKEHIRO
HIWATARI YOSHINOBU
MATSUMOTO SHINTAROU
