AC Interference Corrosion of Buried Metal Pipelines

A simulation test fitting of AC interference corrosion of buried metal pipelines was established, and the influence of AC current density on corrosion behavior was studied. The rate of AC interference corrosion was calculated by weight loss method. The deposition of corrosion products on the steel surface was observed and the microscopic morphology of corrosion products was observed by scanning electron microscopy. The AC currents in different test periods were monitored. The results show that, if the AC interference is applied by resistance coupling method, the severity of AC interference corrosion will be directly related to the AC current. And if the output of AC power supply is not adjusted during the test, the AC current will decrease with the deposition of dense corrosion products. The character of corrosion products has a great influence on AC interference corrosion.