A SURVEY OF ARGENTINEAN ATMOSPHERIC CORROSION .1. ALUMINUM AND ZINC SAMPLES

The atmospheric corrosion of aluminium and zinc samples exposed at six test sites with known ambient parameters in Argentina was investigate d after different outdoor exposition periods. Corrosion damage was det ermined by weight-loss measurements. Both D.C. and A.C. electrochemica l techniques, performed in 0.1 M Na2SO4 solution employing the exposed face of the test samples, were used to characterize the protectivenes ses of the surface layers generated on the metals at different exposur e times during the atmospheric corrosion process in the distinct envir onments. The time dependence of corrosion rates as compared with the w eight-loss data as well as with information from SEM and EDAX observat ions of the rusts concerning the structure and morphology of surface c orrosion products and the presence of pollutants.