Abstract
With rapid development of the economy, more and more power transmission, railway systems and oil/gas pipelines have been constructed in recent years. There have been many cases of pipelines crossing or paralleling to adjacent high-voltage transmission lines or railways. Corrosion caused by AC or DC interference is increasingly prominent and has received increasing attention for buried pipelines.
In this work, a crevice cell was constructed to simulate the local environment on the surface of pipeline steel under disbonded coating in a soil environment. Corrosion behavior of X80 pipeline steel under stray current interference is investigated in the crevice cell. The results show that the AC interference shifts the local potential to the negative direction and markedly increases anodic dissolution of the steel. The attack of pipeline steel at the coating defect is the most serious, while corrosion attack slightly alleviates under the coating disbondment. Influence of stray current interference on corrosion behavior of pipeline steel under the coating defect was discussed from aspects of the commutation effect of AC interference, the irreversibility of anode reaction and effect of AC on the double layer structure at steel/solution interface.
Corrosion Behavior of X65 and X80 Pipeline Steels under AC Interference Condition in High pH Solution