CONJOINT ACTION OF CO2 CORROSION AND RECIPROCATING SLIDING WEAR ON PLAIN CARBON-STEEL .2. ELECTROCHEMICAL STUDIES

The presence of sliding contact between metals in a corrosive medium significantly affects the metal loss rate of the surfaces in contact. In this study, corrosion tests were carried out on plain carbon steel undergoing sliding wear in CO2 saturated 3% NaCl solution with and without an amine corrosion inhibitor. Corrosion rates of the sliding surfaces were estimated using the polarization resistance technique. Sliding wear tests were carried out using steel specimens sliding against each other and steel specimens sliding against corundum specimens both continuously and intermittently. The corrosion rates of the specimens increased with the increase in contact pressure in the presence and absence of the corrosion inhibitor. The inhibitor decreased the corrosion rates for all of the specimens throughout the range of applied contact pressure. The corrosion rates of the specimens subjected to continuous sliding contact were higher than those undergoing intermittent sliding contact. The wear rate of a continuously sliding specimen in the absence of corrosion was determined by the application of cathodic protection and compared to the corrosion rate and the corrosion wear rate under the same loading conditions. The relative contributions of corrosion and wear to the overall metal loss are discussed.