Failure Mechanisms in Pipeline Epoxy Coatings

This paper presents the result of an experimental study of the corrosion behavior of epoxy-coated steel specimens. The spray-coated X65 steel samples were immersed in HCL solutions with varying pH levels. The effects of water adsorption and corrosion were studied via weight gain measurements and microscopic studies. The initial adsorption of fluid resulted in increasing weight gain prior to the weight loss that followed the onset of film delamination/debonding. The underlying mechanisms of corrosion are also elucidated for the steel substrate at different stages of exposure. The delamination is modeled using fracture mechanics concepts and discussing the implication of the current work for robust pipeline design.