Failure Analysis of Corrosion Perforation of L290 Oil Pipeline

The pipe leakage occurs in a station after three years of service. By means of macroscopic inspection, nondestructive testing, physical and chemical properties testing, scanning electron microscopy and energy spectrum analysis, the causes of pipeline failure were determined. The results show that the physical and chemical properties of the leakage pipeline meet the technical requirements. The anticorrosive coating for pipeline is failed, and the thinning of the corrosion of the exterior wall is serious. The environment containing water and corrosive ions provides the basic condition of corrosion.The block corrosion cell caused by pitting induced by Cl^- enrichment promotes the development of corrosion pit along the thickness direction until the perforation.The leakage failure of the pipeline is mainly caused by external corrosion perforation caused by the failure of the pipeline anticorrosive coating.