Study of criterion for assuring the effectiveness of cathodic protection of buried steel pipelines being interfered with alternative current |
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| Authors: | X He G Jiang Y Qiu G Zhang X Jin Z Xiang Z Zhang H Tang |
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| Affiliation: | 1. College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (P. R. China);2. Huazhong Natural Gas Subsidiary of PetroChina Pipeline Company, Wuhan 430074 (P. R. China);3. Dwell Company Limited, PetroChina Engineering Company, Ltd, Beijing 100085 (P. R. China) |
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| Abstract: | Interference of alternative current (AC) on corrosion of X65 steel was investigated in soil. It was observed that the unfavorable effect of interfering AC was able to be effectively inhibited by increasing the direct current density of the cathodic protection (CP) system. A clear correlation was established between the CP current density and the tolerable AC current density. This led to a new criterion for assuring the effectiveness of CP of buried pipelines being interfered with AC. Field experimental results on a buried pipeline running below a 500 kV transmission line showed that the criterion could satisfactorily predict the risk of AC interfering on the CP system. |
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| Keywords: | AC corrosion buried pipeline cathodic protection criterion |
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