Some consideration in determining corrosion rates from linear polarization measurements

Abstract

An i vs η relationship is presented for the aqueous corrosion of a metal in those cases in which the cathodic partial reaction is under mixed control and the anodic partial reaction is under mass-transfer control. A general equation for the “polarization resistance”, from which it is possible to obtain two limiting cases corresponding to the activated control and the mass-transfer control for the cathodic reaction, is also presented. When the anodic partial reaction is under activated control, these limiting cases correspond to those developed by Stern and Geary 1 and Stern 2 respectively. Determination of corrosion rate from linear polarization data is analysed on the basis of the equations developed.