Characterization of Corrosion Products and Corrosion Mechanisms on Automotive Coated Steels Subjected to Field and Laboratory Exposure Tests

Automotive and associated industries investigated cyclic test methods for automotive finishes on steel. The goal was to develop a method which adequately relates to research, development and quality control needs for automotive steel finishes. This paper compares corrosion products and morphologies of attack on materials exposed to on-vehicle tests (Montreal, Quebec and St. Johns, Newfoundland) to the same materials exposed to selected laboratory tests. A variety of analytical tools was applied to compare laboratory and field tests with respect to corrosion mechanisms. A reasonable correlation was established between accelerated test H (PC-4) and field exposed specimens.