Evaluation and Characterization of Anti-Corrosion Properties of Sol-Gel Coating in CO₂ Environments

Corrosion is a major oilfield flow assurance problem with coatings being commonly used by industry as a barrier to electrochemically active species. In recent years, studies on sol-gel materials have drawn an increased interest, gaining more recognition as an alternative to conventional coatings due to many promising properties including hardness, wear resistance and thermal stability. In this work silica inorganic sol-gel coatings were developed and studied in order to optimize their physico-chemical properties with particular attention to their corrosion resistance. To evaluate the protective properties, stainless steel 304 coupons coated with inorganic sol-gel coatings were subjected for a month to a CO2 corrosive environment. The kinetics of the degradation process were monitored throughout by Electrochemical Impedance Spectroscopy (EIS). Besides EIS, electron microscopy was used to characterize the coating morphology and to examine material degradation. Chemical changes in the coating were monitored by infrared (IR) spectroscopy while adhesion and wear resistance characteristics of coatings were studied through scratch tests and erosion tests respectively. A mechanistic understanding of the coatings’ behaviour has been achieved which links the material performance to its characteristics. Moreover, findings in this study advance the knowledge needed to improve coating formulation.