Comparative behaviour in terms of wear and corrosion resistance of galvanized and zinc-iron coated steels

Materials degradation due to simultaneous chemical and mechanical effects may occur under a variety of conditions. Galvanized and zinc-iron electrodeposited steels are widely used to protect automobile bodies against corrosion. In such applications, it is important to investigate the electrochemical and tribological behaviour of the coatings, in order to understand the behaviour of those surfaces in a tribological contact exposed to a corrosive environment. In the present paper, the evolution of open circuit potential, for both surfaces, was monitored during reciprocating sliding against an alumina pin in a 3% NaCl solution. The coatings are compared in terms of electrochemical behaviour by polarization tests, open circuit potential and friction coefficient during sliding; and loss of mass after sliding. The surface morphology, after sliding, was examined by SEM. Under the experimental conditions of the present study, the results found in terms of corrosion and wear resistance could be correlated to the differences in morphology, rugosity and composition of the two analysed surfaces