Search

Potentiodynamic and cyclic voltammetric studies were carried out on nickel in borate buffered saline (pH = 8.49). The anodic excursion spans of nickel in borate buffer solution do not involve active/passive transition. The passive film starts to break down in the presence of Cl-ions, which causes pitting damage. The data reveal that the increasing Cl−concentration and solution temperature shifts the Epitto the active direction while the increasing in scan rate shifts the Epitto the positive direction. The pitting potential (Epit) shifted in a positive direction when increasing concentrations of Wo4−2and MoO4−2anions were added to a borate buffer solution containing Cl−ions, showing that the additional anions had an inhibitory influence on the pitting corrosion. While the NO3−anion is ineffectual as an inhibitor and rather speeds up pitting corrosion, the NO2−anion has a slight inhibitory impact on pitting corrosion.