Corrosion Monitoring using Polarisation Resistance Measurements: I. Techniques and correlations

Abstract

Techniques for the measurement of polarisation resistance, and the determination of proportionality constants for the conversion of polarisation resistance to corrosion rate, are briefly discussed. Studies of the polarisation resistance of iron, aluminium, copper and nickel and their alloys, and other miscellaneous metal and alloy systems, in a wide variety of environments, are reviewed. A selection of proportionality constants are quoted. Very few problems have been cited in the literature concerning thecorrelation of corrosion rates calculated from polarisation resistance data for iron and aluminium and their alloys with corrosion rates calculated using Tafel extrapolation and/or weight loss techniques. The situation is less clear for copper and nickel and their alloys, although many workers have claimed that, in these systems too, good correlation can be achieved.