Passivation kinetics of zircalloy-4 electrode in mineral acids under potentiodynamic conditions

The E/I response of a zircalloy-4 electrode in mineral acids is examined at room temperature under potentiodynamic conditions. On electrodes that have been mechanically polished and cathodically polarized, growth of the oxide phase, ZrO₂, follows the formalism of the Cabrera-Mott model of high field assisted formation of thin oxide films. It is possible to propose a reaction model based on the potentiodynamic experimental parameters, in which the rate determining step is attributed to ionic transfer at the metal-oxide interface.