Stress-corrosion cracking initiation and propagation behavior of single alpha-phase titanium alloys was investigated in an hydrogen generation electrode region for a long duration. According to the X-ray diffi'action peaks, titaafium hydride was found on the surface of the specimens. A definite relationship between formation of hydride phases and crack initiation was concluded based on microscopic observation of surfaces and cross sections of samples. A layer of titanium hydride started to grow from the titanium surface to the interior. When the thickness of the layer reached a critical value, the hydride layer was fractured mechanically. Then, a hydride layer started to grow at the tips of the crack formed, and the newly formed hydride layer starts cracking mechanically.
Keywords: alpha-phase titanium alloy, stress-corrosion cracking, hydride