SIMULATION OF HIGH-TEMPERATURE CORROSION BEHAVIOR OF Ti6Al4V ALLOY IN MARINE ENVIRONMENTS

High-temperature oxidation and corrosion behavior of Ti6Al4V alloy at 650 °C for 1000 h were investigated using a salt mixture (25 w/% NaCl and 75 w/% Na2SO4) as the thermal corrosion medium. The mass increase due to the alloy’s oxidation and thermal corrosion were analyzed quantitatively. The surface morphology and cross-sectional structure of the alloy after oxidation and thermal corrosion were scrutinized and analyzed via X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Results show that Ti6Al4V alloy exhibits a certain antioxidant property in a high-temperature oxidation environment at 650 °C, but this antioxidant property is gradually weakened with the prolongation of the oxidization time. The synergistic effect of oxygen and hot salt further accelerates the corrosion degradation of the oxide layer of Ti6Al4V alloy in the high-temperature hot-salt environment at 650 °C.