| 摘要 |
<p>PROBLEM TO BE SOLVED: To promote the brittle crushing of a Ti scrap caused by hydrogen by subjecting the Ti scrap composed of Ti or a Ti alloy to hydrogen absorbing treatment and the succeeding hydrogenation treatment in a gaseous hydrogen atmosphere and also executing at least to hydrogenation treatment in the gaseous hydrogen atmosphere under pressure. SOLUTION: Preferably, hydrogen absorbing treatment is executed at 600 to 700 deg.C, and hydrogenation treatment is executed at 400 to 550 deg.C in a gaseous hydrogen atmosphere under 1.3 to 3.5 atmospheric pressure. It is also preferably that, after the hydrogen absorbing treatment and the succeeding hydrogenation treatment, dehydrogenation treatment is moreover executed. When hydrogen is absorbed into a Ti scrap by the hydrogen absorbing treatment, and a hydride (TiH2) is produced by the hydrogenation treatment, the Ti scrap expands. By this expansion, strains are produced in the structure of the Ti scrap to generate cracks, and brittle crushing occurs in the Ti scrap. The process of from the absorption of hydrogen through the production of the hydride to the brittle crushing occurs successively from the surface layer of the Ti scrap.</p> |
