Abstract: Butt welding test for the high temperature titanium alloy Ti60 was carried out by laser welding. The surface forming state and macrostructure morphology of the welded joint were observed. And the laser welded joint was annealed at 600, 750 and 900 ℃, respectively, and the microstructure, hardness, residual stress and tensile properties at room temperature of the welded joint annealed were tested and analyzed by means of metallographic microscope, hardness tester, X-ray residual stress detector and tensile testing machine. The results show that with the increase of annealing temperature, the α′ needle-like structure content in the fusion zone of the laser welded joint of the high temperature titanium alloy Ti60 gradually decreases, while that in the heat affected zone gradually increases, and the α phase content in the base metal zone gradually increases. The residual stress of the welded joint gradually decreases. When the annealing temperature exceeds 750 ℃, the residual stress remains basically unchanged. The tensile properties of the welded joint are optimal after annealing at 750 ℃. As the annealing temperature increases, the hardness of the melted zone and heat affected zone of the welded joint gradually decreases, while the hardness of the base metal zone is higher after annealing at 900 ℃ than that after annealing at 600 ℃ and 750 ℃.

Key words: Ti60 titanium alloy, laser welding, microstructure, mechanical properties