Application of the Polarization Resistance Method to the Study of Lead Corrosion in Sulphuric Acid

Abstract The corrosion rates and their evolution with time of lead alloys in hot‐concentrated sulphuric acid have been evaluated through polarization resistance measurements. For the case of alloys capable of being self‐passivated and of retaining the passive state under the exposure conditions, accurate corrosion rates can be predicted from the electrochemical data. On the other hand, some special problems are associated with the application of the polarization method to lead alloys with exhibit alternating changes of corrosion potential between an active and a passive state. Nevertheless, the method, with some slight modifications, continues to be effective for determining corrosion rates although to a lesser degree of accuracy than with stable alloys. On the basis of the results obtained, the different mechanisms of lead alloy corrosion in sulphuric acid are outlined.