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An extensive atmospheric corrosion test program to simulate automotive field conditions has been undertaken. The aim of this project is to identify the necessary and sufficient key corrosion variables in appropriate dosage levels in order to design an indoor general purpose accelerated corrosion test. This approach is based on a careful study of outdoor conditions that an automobile typically would encounter along with inputs from current understanding in the area of corrosion and material properties. A 26-3 factorial design was used to implement this test program. Simulating conditions such as humidity, temperature cycling, acid and/or salt depositions, generation of dew and the presence of minute amounts of air pollutants have been achieved by the design and implementation of a high performance climate chamber. A large matrix of painted metal substrates and some bare metal samples along with previously studied AISI samples constitute this study.

Electrochemical Impedance Spectroscopy (EIS) and Thermal Wave Imaging (TWI) are complementary techniques which can be used to detect and estimate Impact Induced Corrosion (IIC) at the metal-polymer interface. This paper describes the use of the above techniques to detect Impact Induced Corrosion in a variety of pre-coated and painted sheet steels. It has been possible to show, that IIC is a threshold phenomenon and depends on the type of galvanized coating. Evaluation of IIC, using a high performance indoor accelerated test and preliminary data from the proving grounds are presented in this paper.