Abstract
The corrosion forms of automotive body panels are various. One of the representations is a corrosion pitting and its propagation on the lapped portion by galvanic corrosion. But it has been difficult in correlation analysis about the corrosion propagation rate and mechanism of pitting and the actual automotive body in field. This present study interprets experimentally the rust pitting occurrence mechanism on the lapped panels through experimental methods. And field car investigation was executed for correlation analysis with experimental results. This paper compares corrosion propagation rate by pitting on hot-dip galvannealed steel sheets with corrosion forms in the automotive field condition. The research fundamentals which make it possible to predict the pitting occurrence and propagation on the lapped panels in the actual vehicles are given.