CENTRIFUGAL CASTING METHOD ENABLING PREVENTION OF INNER SURFACE DEFECT

摘要

PURPOSE: To prevent the inner surface defect by casting molten cast metal into the inner surface of a heat insulating cylinder which is arranged in the inner part of a metallic mold for centrifugal casting and rotated together with the metallic mold, and solidifying molten metal layer while supplying foggy cooling water into the inner surface of the molten metal layer formed on the inner peripheral surface of the heat insulating cylinder. ;CONSTITUTION: The heat insulating cylinder 2 is arranged in the inner part of the metallic mold 1 for centrifugal casting and the molten cast metal 5 is cast into the inner surface of the heat insulating cylinder 2 rotated together with this metallic mold 1 for casting. While supplying the cooling water 4 in the foggy or raindrop state into the inner surface of the molten metal layer formed in the inner peripheral surface of the heat insulating cylinder 2, the molten metal layer 5 is solidified. On the inner surface of the molten metal layer 5, innumerable solidified particles enclosing impurities of gas, etc., are formed and when these particles shift to the inner surface side of the heat insulating cylinder (metallic mold) 2 by action of the centrifugal force, all or a part of these particles is remelted. By this method, when the molten metal layer 5 solidifies, the impurities are made to be in the condition of uniformly dispersing in the thickness direction of the casting, and the inner surface defect in the cylindrical casting is prevented, and as the crystal structure becomes equiaxed crystals, the mechanical property is improved.;COPYRIGHT: (C)1994,JPO