Fracture risk assessment of trunk oil pipeline by corrosion fatigue mechanism of service defects development

Abstract

Engineering estimations of the corrosion fracture velocity of oil pipelines have been given, which include both mechanical and physical-chemical interaction operation factors of strained material with workspace. Characteristics of cyclic corrosion crack resistance of a pipe metal of the exploited oil-trunk pipeline with the regard for operating production factors have been defined. New data about corrosive and fatigue failure of pipes in dependence on the initial sizes and forms of their detected defects have been obtained. Cyclic used and unused pipe investigated steel crack resistance charts have been compiled. Also, it has been established, that aqueous corrosive environments (soil and distilled water) essentially influence the fatigue failure propagation process in the investigated steel.