Analysis of corrosion failure causes of hongjing line crude oil pipeline

Abstract Pipeline corrosion occurred somewhere in the Hongjing Line crude oil transmission pipeline. In order to investigate the cause of pitting perforation, the corrosion perforation of pipeline was analyzed by optical microscope, scanning electron microscope, fluorescence quantitative PCR and X-ray diffraction analysis, combined with the corrosion simulation experiment of weightloss method. Results On the surface, the pipeline material (L360) met the requirements of API5L standard, and the corrosion form was perforation caused by pitting on the inner wall. The main corrosion products are Fe 2 O 3 , FeCO 3 and FeS. It is found that the concentration of Cl − in the sedimentary water is as high as 30363.8 ppm, which indicates that the main reason for the corrosion of the crude oil pipeline is the pitting corrosion caused by Cl − .