Application of Resistometric Sensors for Real-Time Corrosion Monitoring of Coated Materials

Highly sensitive resistometric sensors were applied for the real-time corrosion monitoring of carbon steel protected with a polyolefin coating with and without an inhibitor under static and dynamic atmospheric and immersion conditions. The results were compared with conventional electrochemical impedance spectroscopy (EIS) data. An increase in the coating thickness from 20 µm to 50 µm and an addition of 1wt.% tannic acid significantly improved the coating corrosion stability. Based on the real-time corrosion data, the drying stage of atmospheric exposure in a chloride-rich environment was found to be the most critical. The highest corrosion rate was detected at 50% relative humidity when the electrolyte corrosiveness in coating defects reached the maximum. Resistometric sensors have the potential to become an interesting alternative for evaluating coating performance and degradation mechanisms in both laboratory and industrial applications.