PURPOSE: To achieve an efficient operation by forecasting the degree of superheat of molten metal to accomplish a designing of melting equipment and a simple setting of operating conditions while molten metal is kept at the degree of superheat suitable for casting.
CONSTITUTION: A high frequency current flows through a high frequency induction coil 20 arranged outside a crucible 12 for melting to perform an induction heating of a material 22 charged in the crucible 12. The material 22 induction heated is held by molten metal 22d melted keeping the bottom part thereof contacting an internal bottom part of the crucible coagulated in such a manner that the molten metal is set upright by an electromagnetic force in no contact with an internal wall surface. An input P (kw) of a high frequency power source for the high frequency induction coil 20, the radius R (mm) of the internal bottom part of the crucible 12 for melting and the degree of superheat ΔT(C°) of the molten metal 22a are set to meet a relationship of P/R2=ΔT (0.0008-0.002).
DEMUKAI NOBORU (JP)