Corrosion of the steel appliqué used in armor kits for HMMWV has been observed to be severe.  This is particularly true in the faying surface region where the steel armor comes in contact with aluminum components of the vehicles.  The US Marine Corps has sought to reduce this corrosion with the application of rugged coating system.  The effectiveness of this coating system compared with other alternatives was studied.  Coated samples were exposed to a test environment consisting of a combined cyclic accelerated environment and vibration testing.  Visual analysis and Electrochemical Impedance Spectroscopy (EIS) were used to evaluate the performance of the coatings tested.