Influence of the composition of working fluids on flow-accelerated organic coating degradation: Deionized water versus electrolyte solution

Corrosion protective coatings are known to degrade due to moisture exposure. To predict coatings service lifetime, acceleration tests are necessary. We employ flowing deionized water to accelerate coating degradation. Coating barrier properties are found, via electrochemical impedance spectroscopy (EIS), to decrease as flow rate (Q) increases, similar to findings for coatings in NaCl solution. EIS modulus decreases more for coatings in deionized water than those in electrolyte solution. Topographical characterizations show severe coating blistering in deionized water immersion with higher Q, but not in electrolyte solutions. Deionized water is thus believed to accelerate more aggressively the degradation than electrolyte solution.

► Deionized water with various flow rates is used to accelerate coating degradation.
► Electrochemical impedance spectroscopy is used to quantify coating degradation.
► Coatings show faster degradation in working fluids with higher flow rates.
► Deionized water deteriorates coatings more aggressively than electrolyte solutions.
► Immersion in flowing fluids is an effective acceleration test method for coatings.