TAPPING CONTROL METHOD FOR LEVITATION MELTING

摘要

PURPOSE: A tapping control method for levitation melting is provided to control tapping promptly and smoothly by discharging cooling inert gas into the tapping part when carrying out tapping operation after performing levitation melting, thereby temporarily solidifying the lower part of levitation molten metal. CONSTITUTION: The tapping control method for levitation melting comprises the steps of charging a target metal for levitation melting into a crucible(20) at upper and lower sides of which electromagnetic coils(51,52) are arranged along the outer circumference of the crucible; levitation melting the metal charged into the crucible by impressing frequency, electric power and current to the electromagnetic coils; tapping the levitation molten metal by increasing a current value impressed to an electromagnetic coil(51) installed at the upper side of the crucible in the electromagnetic coils(51,52); simultaneously turning a current value applied to the electromagnetic coil(51) of the upper side of the crucible to a current value during initial levitation melting when stopping tapping as occasion demands during tapping, and partially cooling the lower side of the molten metal(13) by injecting an inert gas onto molten metal at a high speed through a nozzle inserted into the circumference of the crucible with the nozzle being directed from the lower side to the upper side of the crucible; and performing levitation melting of the metal again after performing partial cooling and stopping supplying of the inert gas.