Effect of Al2O3 particles on the adhesion, wear, and corrosion performance of epoxy coatings for protection of umbilical cables accessories for subsea oil and gas production systems

Abstract

Umbilical cables accessories of subsea oil and gas production systems are exposed to very high mechanical stresses, abrasive wear, and continuous electrolyte action in submerged condition. Epoxy-based composite coatings with ceramic loading have been studied for providing protection to the accessories. By adding micro-Al2O3 particles to the polymeric matrix, the corrosion and wear properties are expected to be improved without a significant impact on the cost as compared with unmodified epoxy coating. In order to evaluate the tribological properties, adhesion and micro-scale abrasive tests have been performed on epoxy before and after loading of 26vol.% micro Al2O3 particles. The results showed that wear resistance and adhesion to the substrate of ceramic-loaded epoxy increased by 30% and 50%, respectively. Electrochemical impedance spectroscopy tests were also performed and higher resistances of epoxy with ceramic loading were confirmed, which indicate a more efficient barrier against electrolyte permeation. In addition, coatings with thicknesses of 120μm, 240μm, and 360μm were evaluated and the results showed that the resistances of both coatings increased with the increase in the thickness. Thus, the loading of micro Al2O3 particles into epoxy resin matrix increased its adhesion, wear, and corrosion resistances without significant impact on the cost, which renders the use of this coating in umbilical accessories feasible.