| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a water-cooled copper crucible for the consumable electrode type vacuum arc melting capable of minimizing a cut part by suppressing the generation of defects at the bottom part of an ingot. <P>SOLUTION: A recessed part 6 having height lower than that of the center part is provided at the peripheral part of the surface of a base board 2 constituting the bottom part of the crucible. The recessed part 6 is an annular groove for example and is designed so that r/R≥0.6 is satisfied when a groove radius is r and an inner radius of the crucible is R. The recessed part is designed so that 0.3 cm≤α≤3.0 cm is satisfied whenαis (recessed part volume) / (crucible cross-section area). Since a molten metal generated immediately after the start of melting operation flows into the recessed part 6 and gathers at the peripheral part, the cooling of the molten metal in the crucible is suppressed and the generation of the defects at the bottom part of the ingot is suppressed. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
