Effect of Alternating Current and Sulfate-Reducing Bacteria on Corrosion of X80 Pipeline Steel in Soil-Extract Solution.

Jin Xu,Maocheng Yan,Tangqing Wu,Yunlong Bai,Cheng Sun,Yongchang Qing

doi:10.3390/ma12010144

Abstract

AC corrosion has been considere d as a threat to the corrosion of buried pipelines. Effects of sulfate-reducing bacteria (SRB) and alternating current (AC) on corrosion of X80 pipeline steel in soil-extract solution were investigated by electrochemical and surface analysis techniques. AC current can inhibit the growth of planktonic and sessile SRB. The corrosion current density of steel with 10 mA/cm2 AC current is about nine times bigger than that without AC current. Corrosion morphology changes from small pitting to large pitting holes with increasing AC current density. Corrosion of steel with SRB and AC current is controlled by both active dissolution of iron and film degradation.

Highlights

Stray currents caused by high voltage facilities, such as high power transmission lines and electrified railways, can enhance the corrosion of buried pipeline steels, eventually resulting in significant failures of the pipelines [1,2,3]
Studies of alternating current (AC) influenced corrosion can be traced back to the early period of the 1900s. These early investigations showed that the corrosion rate of metal induced by AC current was approximately 1% of that by an equivalent amount of direct current (DC), [4] AC influenced corrosion had not been considered as a threat to the integrity of pipelines until a pipeline accident caused by AC current occurred in Germany in 1986, stimulating interest in this research topic [3,5]
The results showed that the AC current inhibits the sessile sulfate-reducing bacteria (SRB) cell growth, celland growth, and inhibition with increasing inhibition increases increases with increasing

Summary

Introduction

Stray currents caused by high voltage facilities, such as high power transmission lines and electrified railways, can enhance the corrosion of buried pipeline steels, eventually resulting in significant failures of the pipelines [1,2,3]. Studies of alternating current (AC) influenced corrosion can be traced back to the early period of the 1900s. These early investigations showed that the corrosion rate of metal induced by AC current was approximately 1% of that by an equivalent amount of direct current (DC), [4] AC influenced corrosion had not been considered as a threat to the integrity of pipelines until a pipeline accident caused by AC current occurred in Germany in 1986, stimulating interest in this research topic [3,5]. Goidanich et al found that AC current density higher than 10 A/m2 gave rise to a considerable increase in the corrosion rate of the metal.

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Conclusion