| 摘要 |
<p>PURPOSE: To manufacture a material of a high melting point metal product by using a high melting point metal material containing volatile impurities such as sponge Ti, etc. CONSTITUTION: A cylindrical refractory 3 is provided in the crucible 1 of a cold crucible melting and casting apparatus. Atmosphere gas flow 9 in the crucible is controlled to prevent the deposition of volatile impurities (Mg, MgCl2 , etc.) on the wall in the crucible, and to discharge it out of the crucible. The disposing conditions of the refractory 3 are that the lower distance (Lg) in the height direction between the lower end 2b and the upper end 3a of an induction coil is in the range of 0.25 to 0.75 times as large as the coil height (L) and a gap distance between the outer wall surface and the inner wall surface of the crucible is 1mm or more and 0.25 times or less as large as the the inner diameter of the crucible. Thus, the aging decrease of the melting efficiency is prevented, and continuous melting can be conducted for a long time with stable and high productivity.</p> |
