Perforation Failure Analysis of N80 Pipe

Early perforation failure occurred in underground usage of N80 pipe. Reasons for the failure of the N80 pipe were analyzed through macro corrosion morphology, chemical composition of the pipe material and metallographic structure. And the corrosion morphology and composition of corrosion products on the cross section of the failed N80 pipe were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The results indicate that the main reasons for perforation failure of the N80 pipe was electrochemical corrosion, and Cl^- in the medium transported by the pipe played a major role in the corrosion process.