A method for the production of titanium and titanium - alloys with a fine acicular microstructure.

摘要

PURPOSE:To obtain Ti and Ti alloy excellent in fracture toughness and fatigue characteristics and having a fine acicular structure by subjecting Ti and Ti alloy containing small amounts of hydrogen to hot rolling and to cooling under respectively specified conditions and then carrying out dehydrogenation and annealing in vacuum. CONSTITUTION:Ti, alpha Ti alloy, and alpha plus beta Ti alloy to which 0.02-2wt.% hydrogen is incorporated by means of heating in a hydrogen-gas atmosphere are heated up to a temp. region between the beta-transformation points of these Ti-type metals and 1100 deg.C and hot-rolled in the above temp. region at =30% draft, and hot rolling is finished at a temp. in the beta-single phase temp. region and successively these Ti-type metals are cooled down to =400 deg.C and reheated in vacuum to undergo dehydrogenation and simultaneously annealed, or, the above Ti-metals are heated up to a temp. between beta-transformation point and 1100 deg.C, cooled temporarily down to =400 deg.C, heated again up to a temp. between-transformation point and 1100 deg.C, and hot-worked in the above temp. region, and then, hot working is finished in the beta-single phase temp. region and the Ti-type metals are cooled again down to =400 deg.C and subjected to dehydrogenation and annealing by means of vacuum heating treatment. By this method, the Ti-type metals having fine acicular crystalline structure and superior characteristics can be obtained.