Evaluation of Tensile, Impact and Fatigue Crack Growth Rate of Epoxy Based Coatings used as a Lining for Crude Oil Storage Tanks
Fatigue is one of the main causes of failures in petroleum storage tanks. In order to assess the safety of the tank metal and coatings, the expected fatigue failure needs to be estimated. In this paper, the tensile, impact and fatigue resistance of three types of epoxy based coatings (pure, Phenol Novolac and reinforced by glass-flake) used as lining for crude oil storage tanks were studied using experimental method and finite elements method (FEM). Both experimental test and (FEM) were conducted on uncoated and coated ASTM A537 C1 steel in case of single and double layers. The test results showed that the applied coating improves the mechanical properties and increases of fatigue crack resistance. The fatigue crack growth rate is influenced by compositions of epoxy coating and an amine-adduct cured epoxy coating reinforced with glass-flakes show more resistance to fatigue cracks compare to amine cure by Novolac or pure epoxy. Microscopic observation of fatigue tests of specimens show the crack propagations is uniform, stable and linear types.