Perforation corrosion of automotive materials: comparison between laboratory and field exposures

Abstract

Two of the most important testing parameters, the wet/dry ratio and the temperature, were varied in order to study their influence on the extent of perforation corrosion of automobile materials. The results are compared with results from field exposures performed at the marine site of Bohus Malmön (Sweden) and with results from mobile exposure. In situ measurements of the galvanic current and the electrochemical impedance of the confined surface were used to determine the degree of macrowetness and the corrosion rate respectively. From the results it is shown that both the drying time and the temperature are important factors when designing cyclic corrosion tests for perforation corrosion of auto motive materials.