Anodic and chemical oxidation to improve localized corrosion resistance of pure titanium

The corrosion behavior of commercially pure titanium (UNS R50400, ASTM GRADE 2) was investigated in presence of aggressive, bromides containing solution reported to cause more severe localized corrosion compared to chlorides. To enhance localized corrosion resistance of the metal, chemical oxidation treatments were performed using NaOH 10 M solution at room temperature and at 60°C. Treatment duration effect on final corrosion resistance of samples was investigated spanning from 1 h to 72 h. After treatment optimization, the best one was compared to anodic oxidation at low potential. To further increase corrosion resistance, annealing at 400°C and 600°C was performed after chemical oxidation and the resulting samples were tested in bromides containing solution.