| 摘要 |
<p>PURPOSE:To prevent the falling of a part of an electrode in arc secondary melting for a nickel-containing titanium ingot. CONSTITUTION:In the secondary melting, a slab 2 is welded to an ingot 1 as electrode. Because an extremely brittle Ti2Ni layer is-precipitated in the vicinity of joint part, cracks are developed from the joint surface between the ingot and the slab in the course of melting, and the falling of the electrode is brought about. In the secondary melting, a part or the whole of the electrode prepared by primary melting is heated up to a temp. not lower than the transformation point and cooled rapidly, and secondary melting is done by using the above as electrode, by which a large amount of nickel is allowed to enter into solid solution in titanium and the brittle Ti2Ni layer is practically removed, and as a result, the occurrence of falling can be prevented. In titanium containing 2-11wt.% Ni, heat treatment is done at 800-900 deg.C.</p> |
