ALPHA + BETA TITANIUM ALLOY COLD-ROLLED AND ANNEALED SHEET HAVING HIGH STRENGTH AND HIGH YOUNG'S MODULUS AND METHOD FOR PRODUCING THE SAME

摘要

An object of the present invention is to provide an α+β titanium alloy cold-rolled and annealed sheet having a high strength and a high Young's modulus in the sheet width direction. A titanium alloy sheet in which, when the texture in the sheet plane direction is analyzed, the ratio XTD/XND between the X-ray relative intensity peak value (XTD) in directions close to the sheet width direction and the X-ray relative intensity peak value (XND) in directions close to the normal-to-sheet-plane direction on the (0002) pole figure of the α-phase is 5.0 or more and which contains, in mass %, Fe: 0.8% to 1.5% and N: 0.020% or less and has an oxygen-equivalent Q of 0.34 to 0.55. Annealing of the titanium alloy sheet is performed at not less than 500° C. and less than 800° C. in the case where the cold rolling rate is less than 25% and at not less than 500° C. and less than 620° C. in the case where the cold rolling rate is 25% or more.