| 摘要 |
PURPOSE:To improve efficiency and stabilize operation of vacuum arc melting furnace by detecting variation of pressure in a chamber of a vacuum arc melting furnace, controlling valve opening in vacuum piping and maintaining the pressure in the chamber to the specific setting valve. CONSTITUTION:In the furnace body 6 providing vacuum pump system in the vacuum arc melting furnace, a consumable electrode 2 for melting material inserted through a stringer rod 5 is melted and refined with AC arc to form an ingot 34 in a water cooled crucible 1. Then, the pressure in the chamber 11 of the furnace body 6 is detected with a pressure gage 22. The variation of the pressure is detected with a controller 23 and according to the variation, the opening degree of the control valve 21 in the vacuum piping is controlled. In this result, the pressure in the chamber 11 is maintained to the set value in the range of 1-<3Torr. By this method, gas components and impurities, such as hydrogen, lead, are removed and the yield of the available element, such as manganese having low vaporizing pressure, is improved and the stable operation can be executed.
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