Abstract:The new Ti-6Al-4V-0.5Ni-0.05Ru titanium alloy was designed for oil country tubular goods (OCTG) in the rigorous oil gas exploration environment of China. However, the hot working technology and heat treatment of this new titanium alloy are unclear. The effect of hot rolling process and heat treatment on microstructure and tensile properties of Ti-6Al-4V-0.5Ni-0.05Ru Titanium alloy were investigated by using optical microscopy, mechanical performance test, electron backscatter diffraction (EBSD) analysis and transmission electron microscope (TEM) observation in this paper. The results showed that the hot rolled plate had good deformation ability after 80% deformation rolling in α+β two-phase zone (940℃) andβphase zone (1000℃), no macroscopic cracks were obseved. After hot rolling inα+βphase zone, the single annealing treatment homogenizes the microstructure to a certain extent, but the grain size is still large, and the longitudinal and transverse microstructure of the rolled plate is still quite different. After hot rolling in theβphase, the microstructure is smaller and uniform distribution than that of 940℃ hot rolling, and the morphology of the longitudinal and transverse microstructure is basically the same.With the increase of single annealing temperature, the tensile strength of hot rolled plate decreased and the impact energy increased, when using double annealing treatment, the strength can be improved but the toughness of the plate is reduced.In the same heat treatment process, a good match of strength and toughness can be obtained by increasing the hot rolling temperature.