PURPOSE: To prevent the crack of a base material shell and to prevent the generation of the defective inter-layer adhesion of a clad plate by disposing and fixing a flat metallic core material into a vertical casting mold and attaching a material which shrinks easily in volume with a pouring temp. to at least the short side face thereof, then executing casting.
CONSTITUTION: The flat metallic core material 3 is disposed and fixed to the central part in the broad vertical casting mold 1. A heat resistant and fire- resistant asbestos board or the like which does not melt and burn with the molten metal 4 or porous flame-retardancy-finished org. material or the like 10 which gradually burns and dissipates with the molten metal is attached to at least the short side face 3B of the short side face 3B and top and bottom faces 3C, 3D of the core material 3. A molten metal shell is immediately formed on the surface of the material 3 when the molten metal 4 is poured into the casting mold 1 but the shell is liable to be cracked by the thermal expansion of the material 3. The tensile force to be exerted on the shell is relaxed and the generation of the crack is prevented if there is the material which shrinks easily in volume on the short side face. The generation of the defective inter- layer adhesion arising from the base material crack is thus prevented.
KAWARADA AKIRA
SHIRAISHI MASASHI
KAKIO YASUHIRO
MISHIRO SUKETSUGU
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