Corrosion testing and simulation has played a critical role in the development of corrosion resistant automobiles. Much has been learned over a period of time with respect to the automotive corrosion protection and its assessment. A range of coatings and platings are being used in the automotive sector. In this field of application, designs are very complex and focus is on enhanced vehicle level corrosion protection, given the high corrosion warranty costs.
The objective of the present study was to develop a electrochemical test method to rapidly and quantitatively screen the corrosion performance of automotive coating systems. The present study compares electrochemical results obtained using a linear polarization resistance (LPR) to results obtained via the standard ASTM B117 salt spray test. Salt spray tests were done on a separate series of these coating systems according to ASTM B117, and the results were ranked from 10 (excellent performance) to 1 (very poor performance). Comparison between electrochemical test and the salt spray rankings of the samples suggests a promising correlation between the corrosion rate data and salt spray performance, although additional information is needed to confirm this hypothesis. However, kinetic information that examines the rate of corrosion as a function of time following the introduction of other parameters like welding, sealants over the coating is essential in predicting performance.
