通过现场交直流干扰参数的测试对珠江支线埋地钢质管道的受干扰情况进行了评价,结果表明,该段管道受到严重的交直流混合干扰。使用交流电压参数与交流电流密度参数评价管道的受干扰情况,会得到截然不同的评价结论。阴极保护带来的阴极极化对防腐蚀层破损点周边的局部电阻率有明显的影响。在低电阻率、高极化水平下,可能出现管道的交流电压很低但是交流电流密度很大的现象。

The interference condition of the buried steel pipeline of the Pearl River Branch Pipeline was evaluated by the on site AC and DC interference parameters test. The results showed that the pipeline was subject to serious AC and DC mixed interference. Using AC voltage parameters and AC current density parameters to evaluate the interference of the pipeline, we would get completely different evaluation conclusions. Cathodic polarization caused by cathodic protection had obvious influence on localized resistivity around the damage point of anti-corrosion coating. Under low resistivity and high polarization condition, the AC voltage of the pipeline might be very low but the AC current density might be very high.