| 主权项 |
1. A method for manufacturing a titanium alloy ingot (the titanium alloy being allowable to be pure titanium), comprising the steps of:
(a) melting a titanium material or titanium scrap material (hereinafter referred to as “titanium material”) by a cold crucible induction melting (hereinafter referred to as “CCIM”) in such a manner that the following expression (1) can be satisfied:
y≧700×A−1.2 (1)wherein A =P/(V/S) wherein
y: the period [min] for the melting, A: a thermal balance parameter, P: the applied electric power [kW] in the CCIM, V: the volume [m3] of the melted titanium, and S: the surface area [m2] of the melted titanium, (b) supplying, after the step (a), the resultant titanium material, which has been melted (hereinafter referred to as the “melted titanium material”), to a cold hearth, and separating an inclusion having a large specific gravity which is more than 5 g/cm3 by precipitation inside the cold hearth while a plasma jet is blown onto or an electron beam is radiated onto a surface of the melt of the melted titanium material, thereby yielding a titanium alloy, and (c) supplying, into a mold, the resultant titanium material, in which the inclusion, the specific gravity of which is large, has been separated by precipitation, thereby yielding the titanium ingot. |
