WELDED PIPE OF + TITANIUM ALLOY WITH EXCELLENT STRENGTH AND RIGIDITY IN PIPE-LENGTH DIRECTION, AND PROCESS FOR PRODUCING SAME

摘要

Provided is an α+β titanium alloy welded pipe excellent in the strength and the rigidity in the pipe longitudinal direction, the α+β titanium alloy welded pipe having a composition consisting of, in mass%, Fe: 0.8% to 1.5%, N: 0.02% or less, and the balance: Ti and impurities, and satisfying Q shown in Formula (1) being 0.34 to 0.55. A tensile strength in a pipe longitudinal direction is more than 900 MPa and a Young's modulus in the pipe longitudinal direction is more than 130 GPa. $\mathrm{Q}=\left[\mathrm{O}\right]+\mathrm{2.77}\times \left[\mathrm{N}\right]+\mathrm{0.1}\times \left[\mathrm{Fe}\right]\mathop{\mathrm{image}}$ where [Fe], [O], and [N] represent the amounts of the respective elements contained [mass%].