CHARACTERIZATION OF SYNERGISTIC EFFECTS BETWEEN EROSION AND CORROSIONIN AN AQUEOUS ENVIRONMENT USING ELECTROCHEMICAL TECHNIQUES

Synergistic effects between erosion and corrosion processes on mild st eel (MS) in an aqueous carbonate-bicarbonate solution were studied usi ng electrochemical measurements from a rotating cylinder electrode (RC E) system, A rigorous basis for definition and measurement of the ''pu re'' erosion rate and corrosion rate was adopted so that so-called syn ergism could be analyzed precisely. The total erosion-corrosion rate a nd the corrosion rate in the presence and absence of erosion were meas ured for a range of electrode potentials and rotation velocities. The corrosion rate increased significantly with the introduction of eroden t because of the effect of erosion on corrosion kinetics. The total er osion-corrosion rate under active dissolution and passivation conditio ns essentially was the sum of the pure erosion rate and the measured ( enhanced) corrosion rate, suggesting there was no significant effect o f corrosion on the erosion process. However, in the active-to-passive transition regime, some synergistic effects ascribed to erosion were o bserved (i.e., mechanical damage was enhanced by corrosion).