Corrosion Behavior of Epoxy (SIGMALINE) Coated X65 Steel in some Selected Corrosive Media

Abstract

Like any industry, the economic success of the oil and gas industry can be no swifter than its success in corrosion control/prevention. Some oil and gas industries operate in hostile offshore environment that harbors significantly quite substantially different corrosive agents including ions of chloride, Cl-, bicarbonate (HCO3-), hydrogen sulfide (HS-), sulfide (S-), etc., coupled with gases such as oxygen (O2), carbon dioxide (CO2), just to name a few. Oil and gas structural materials and pipeline steels are made of metals. The interaction amongst these metals and between the metals and the aforementioned corrosive agents in seawater water environment causes metallurgy in-reverse (corrosion) with time. The result of the corrosion process leads to rusting and subsequently, failure of the materials. Understanding the effects different corrosive environments have on materials deterioration doesn’t only drive a better understanding of corrosion control methods and mitigation techniques but also play a pivotal role in preventing oil and gas offshore platform from corrosion attacks. The protection and safety such understanding offers to human and marine lives cannot be overemphasized. Billions of dollars can also be lost by poor corrosion management strategies. Although “corrosion prevention” is an overstatement as this research is concern, “corrosion control” is the diction of choose. Different corrosion control methods including cathodic protection, coating, etc., are possible but epoxy coating was considered for the purpose of this research. An analysis of the corrosion behavior of X65 steel samples coated with epoxy (sigmaline), was carried out in some selected corrosive media of different concentrations. Weight loss measurement was obtained at different time intervals. The corrosion rate of the steel samples were characterized based on weight loss measurements obtained from weighing balance and pH change calculations from corrosion reactions.