Effects of alternating stray current on the corrosion behaviours of buried Q235 steel pipelines
Abstract
Purpose
With the rapid development of rail transportation and energy-delivery systems, such as buried oil and gas pipelines and high-voltage transmission lines, the alternating current (AC) corrosion of buried steel pipelines is becoming more serious. This paper aims to study the corrosion behaviours of Q235 buried steel pipelines induced by the alternating stray current, with a set of indoor simulated experiment apparatuses.
Design/methodology/approach
The corrosion of the coating holidays of the buried steel pipelines at various AC current densities from 0 to 200 A/m2 in the soil-simulating environment was revealed by the electrochemical and weight-loss methods.
Findings
The results showed that the corrosion potential of the steel shifted negatively obviously and the corrosion rate of the steel increased with the increasing of AC current density. At a low AC current density, the negative deviation of the corrosion potential of the steel was small and the increase of corrosion rate was slight. However, the negative deviation of the corrosion potential was remarkable and the corrosion rate was greatly increased at a relative higher AC current density. The geometrical shape of the corrosion images indicated the corrosion forms changed from uniform corrosion to local corrosion due to the increase of AC interference.
Originality/value
Investigation results are of benefit to provide a new strategy to forecast and evaluate the AC-induced corrosion of the buried pipelines which could improve the safety of pipeline transportation.
Keywords
Acknowledgements
The work is supported by the National Key Research and Development Program of China (No. 2017YFF0210404), the Tribology Science Fund of State Key Laboratory of Tribology (No. SKLTKF14A08) and the Science Foundation of China University of Petroleum, Beijing (No. 2462017BJB06, C201602).
Citation
Guo, Y., Tan, H., Wang, D. and Meng, T. (2017), "Effects of alternating stray current on the corrosion behaviours of buried Q235 steel pipelines", Anti-Corrosion Methods and Materials, Vol. 64 No. 6, pp. 599-606. https://doi.org/10.1108/ACMM-01-2017-1748
Publisher
:Emerald Publishing Limited
Copyright © 2017, Emerald Publishing Limited