Corrosion Analysis on Daqing-Tieling Oil Pipeline

Based on the analytical result of corrosion investigation in Daqing-Tieling Oil Pipeline, the external corrosion mechanism and basic law of corrosion distribution of the buried steel pipeline are presented.Taking per kilometer pipeline as an evaluation unit, the corrosion category is divided into 5 typs, that is, "very seriously corrosion", serious corrosion, "medium corrosion", "slight corrosion" and "no corrosion "The evaluation results show that the corrosion of the pipeline is characterized by a high centralization, the corrosion distribution for the "serious corrosion" pipe section presents a tendency to center to upstream and downstream pipe section, and the corrosion distribution in pipe's circumferentia is not uniform. It is pointed out that the micro-cracks in coating is likely formed at 3 or 9 o'clock position of the pipe.