Device Design for In-Situ EIS Measurements of Organic Coatings Under Accelerated Degradation Via Impingement Flow

Abstract

This paper demonstrated a holistic approach to the study of corrosion degradation mechanism of organic coatings using impingement flows. A state-of-the-art impingement flow testing device was developed for the experimental investigations of coating degradation behavior under various fluid flow conditions. The testing device employed Electrochemical Impedance Spectroscopy (EIS) to monitor and quantify the coating performance. This study prepares us for a pathway to investigate the degradation mechanism of coatings using both mechanistic and electrochemical approaches. This paper provided a limited amount of experimental data to show the capability of the current experimental setup. A pigmented marine coating was tested under a 90-degree jet impingement flow of a looped 3.5% wt. NaCl solution. The measured impedance results indicated that the coating barrier property decreased for all tested flow rates. It was also found impingement flow can accelerate the coating degradation process comparing with the standard stationary immersion tests.