ISSN: 0090-3973
Page Count: 5

Electrochemical Impedance Spectroscopy for Monitoring Coating Performance in Condensing Environments

Rosenberg, HS
Research leader,Guild Associates, Inc.,OH,

Syrett, BC
Project manager,Electric Power Research Institute,CA,

(Received 20 August 1993; accepted 10 June 1994)

Abstract

A novel method is described for monitoring coating performance in the thin liquid films found in condensing environments, such as in the corrosive condensate found in flue gas desulfurization (FGD) systems. The method involves exposing coated metal panels to controlled environments, created by atomizing solutions of appropriate composition, in fog chambers. The fog deposits on the coated surface as a thin film that simulates the condensate formed in actual service. The performance of the coatings is monitored in situ by electrochemical impedance spectroscopy (EIS) during periods when the exposed coated surfaces are temporarily flooded with bulk solution having the same composition as the condensate. The method has been used to evaluate the effects of sixteen environmental factors on the performance of eight coatings currently used in FGD outlet ducts.

Keywords:
test method, coating performance, condensing environment, electrochemical impedance spectroscopy (EIS), organic linings, flue gas desulfurization (FGD)

Paper ID: JTE11858J
DOI: 10.1520/JTE11858J
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