Rapid corrosion testing of polymer coated steel using a constant voltage

An alternative to accelerated corrosion performance evaluation, e.g. neutral salt spray test (NSS), is proposed by applying a constant voltage in a corrosive media. In this work, polyurethane coated steels were tested at 3.5 V in a 3.5% NaCl solution. NSS was done to allow comparison with the constant voltage test. Electrochemical impedance spectroscopy (EIS) tests were carried out periodically to study the corrosion procedures. Generally, it takes just 90 h for constant voltage to reach a similar state as NSS after 20 days, confirming that the acceleration rate of the constant voltage method is significantly more rapid than the established NSS test.