直流杂散电流对埋地管道阴极保护有效性的影响分析

Analysis of Influence of DC Stray Current on Effectiveness of Cathodic Protection for Buried Pipelines

为了在杂散电流干扰状态下测试埋地管道的阴极保护电位并评价其有效性,解决杂散电流的腐蚀问题,通过对国内相关标准分析并参考国外标准,找出了杂散电流干扰下阴极保护电位的测试方法,在瞬间断电状态下测出的断电电位作为阴极保护电位,采用极化探头与断电电位测试仪联合使用的方法,完成测试数据的自动记录。参考AS 2832.1—2015,用保护电位正于有效电位的时长比例评价阴极保护的有效性。实际工程应用表明:采用此方法评价的阴极保护失效管道,开挖检查确实存在杂散电流腐蚀现象,可以此判定埋地管道是否采取抗干扰措施。

In order to test the cathodic protection potential of buried pipelines under stray current interference and evaluate its effectiveness and solve the corrosion problem of stray current,a testing method for cathodic protection potential under stray current interference was found by analyzing relevant domestic standards and referring to foreign standards.The outage potential measured under instantaneous power outage state was used as the cathodic protection potential,and a polarization probe and outage potential tester were used in combination,to complete automatic recording of test data.Referring to the AS 2832.1—2015,the effectiveness of cathodic protection was evaluated by the ratio of the duration of the protective potential to the effective potential.Practical engineering applications show that there is indeed stray current corrosion phenomenon in the excavation inspection of cathodic protection failure pipelines evaluated using this method,which can determine whether buried pipelines take anti-interference measures.