METHOD OF MANUFACTURING ROLLED TITANIUM ALLOY SHEETS

摘要

A method of manufacturing a rolled titanium alloy sheet comprises breaking down an .alpha. or .alpha.+.beta. titanium alloy ingot into a slab, working the slab in sequential stages of (A) cross rolling the slab in the .alpha.+.beta. region under a condition of a reduction ratio of at least 1.2 and a crposs rolling ratio of 0.6 to 1.4, (B) annealing the workpiece for recrystallizatlon at a temperature 20.degree. to 100.degree.C, preferably 20.degree. to 70.degree.C, below the .beta.-transus of the alloy, and (C) further cross rolling it in the .alpha.+.beta. region under a condition of a reduction ratio of at least 1.6 and a cross rolling ratio of 0.6 to 1.4, and thereafter heat treating the rolled workpiece for annealing, solution treatment and aging or the like, depending on the intended use of the product. The method may include an additional stage (D) of repeating stages (B) and (C) at least once each. The ingot breakdown is preferably carried out by forging or rolling at a temperature of the two-phase .alpha.+.beta. region to a total draft of at least 30%. The heating prior to the hot rolling operations is preferably effected in an atmosphere at a partial pressure of oxygen of 0.02 atm. or below.