PURPOSE: To obtain fine and almost uniform non-dendritic crystal grains at high productivity with simple equipment by rapidly cooling at least a part of molten metal into solid-liquid coexistent state and holding this state at a semi solid temp. zone for a prescribed time.
CONSTITUTION: At least a part of the molten metal (m) poured from the tapped molten metal supplying tube 14 of a molten metal holding furnace 1 is rapidly cooled into the solid-liquid coexistent state by bringing the molten metal (m) into contact with a cooling body 2. A heat keeping furnace 3 is the one for growing the primary crystal grains and spheridizing by holding the molten metal (m) whose at least a part becomes the solid-liquid coexistent state at the solid-liquid coexistent temp. for the prescribed time, and in the lower part thereof, a continuous caster 4 is arranged. In the continuous caster 4, a tank 42 for cooling water is arranged at the outer periphery of a mold 41 successively arranged just below the temp. holding furnace 3 and also, a water charging port 43 is provided at the inside of bottom part of the tank 42 for cooling water. Then, the cooling water (w) is charged into the outer peripheral part of the metal drawn out after the metallic slurry (m") in the temp. holding furnace 3 passes through the mold 41, and the metallic slurry is rapidly cooled to cast a metallic billet (b).
RIYUU CHI
DOI HACHIRO
AOYAMA SHUNZO
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