ELECTROCHEMICAL AND CORROSION BEHAVIOR OF PLATINIZED TITANIUM ELECTRODES CATHODICALLY POLARIZED IN SEAWATER

The corrosion rates of platinized titanium electrodes (PTE) anodically and cathodically polarized in seawater were compared at current densities of 1.50-2000 A/m2. It was found that in electrodialysis (I = 150-300 A/m2), the corrosion rate of PTE is substantially lower during the cathodic period of polarization than during the anodic period. At current densities of 800 A/m2 and more, the corrosion rates of PTE cathodically polarized become higher than those of PTE anodically polarized, which is due to the destruction of platinum by formation of intermetallic compounds between the platinum and the cations of alkaline-earth metals calcium and magnesium contained in seawater. The destructive action of the calcium ions on platinum in seawater was found to be stronger.