LINEAR CORROSION KINETICS

The kinetic origin of extended linear polarization curves is examined for corroding electrodes. An analytical expression is derived for the deviation of the linear polarization curve from the true curve. Two experimental effects reported in the literature: extension of the ranges of validity for linear polarization curves to 60mV or more, and a large difference in range of validity comparing anodic and cathodic polarization of a given electrode, are both predictable from present kinetic theory. It is shown also that the ranges of validity of both anodic and cathodic linear polarization curves are less than 3mV at some electrodes, e.g. Fe-acid under charge-transfer control. © 1969 Pergamon Press.