动态交流干扰对X70管线钢腐蚀行为的模拟研究  

Simulation Research on the Corrosion Behavior of X70 Pipeline Steel under Dynamic AC Interference

作　　者：曹国飞 邱春斌 赵冬野 CAO Guofei;QIU Chunbin;ZHAO Dongye(PipeChina West East Gas Pipeline Company,Shanghai 200000,China)

机构地区：[1]国家石油天然气管网集团有限公司西气东输分公司,上海200000

出　　处：《材料保护》2024年第11期53-61,138,共10页Materials Protection

摘　　要：为了给电气化铁路附近管道的防腐设计提供参考,基于管道监测数据,研究了不同铁路类型附近管道的动态交流干扰参数特征。通过阴极保护下动态交流腐蚀模拟试验装置,研究分析了高铁类、普通铁路类等动态交流干扰下埋地X70管线钢的腐蚀行为。结果表明:在典型动态干扰周期中,相同阴极保护电位下,动态交流干扰电流密度越高,X70钢腐蚀速率越大。当动态交流电流密度高于100 A/m^(2)时,无论在何种阴极保护条件下,腐蚀速率均高于0.03 mm/a。在动态交流干扰下,随着阴极保护水平的增加,腐蚀速率呈现“马鞍形”,先降低后升高。仅当交流电流密度为30 A/m^(2),且阴极保护水平处于-0.90~-1.15 V(vs CSE)时,腐蚀速率均低于0.03 mm/a。动态交流干扰下,即使管道处于有效阴极保护状态,也会发生腐蚀。In order to provide reference for the anti-corrosion design of pipelines near electrified railways,the characteristics of AC dynamic interference parameters near pipelines of different railway types were studied on the basis of pipeline monitoring data.The corrosion behavior of buried X70 pipeline steel under dynamic AC interference in high-speed and ordinary railways was studied and analyzed through using a dynamic AC corrosion simulation test device under cathodic protection.Results showed that in a typical dynamic interference cycle,a higher dynamic AC interference current density resulted in a higher corrosion rate of X70 steel under the same cathodic protection potential.When the dynamic AC current density was higher than 100 A/m^(2),the corrosion rate was higher than 0.03 mm/a under any cathodic protection conditions.Under dynamic communication interference,as the level of cathodic protection increased,the corrosion rate presented a“saddle shaped”pattern,first decreasing and then increasing.Only when the AC current density was 30 A/m^(2) and the cathodic protection level was between-0.90 and-1.15 V(vs CSE),the corrosion rate was less than 0.03 mm/a.Furthermore,even if the pipeline was in an effective cathodic protection state,corrosion would occur under dynamic communication interference.

关 键 词：X70钢 阴极保护 动态交流干扰 腐蚀速率 腐蚀形貌 腐蚀产物 

分 类 号：TG174.41[金属学及工艺—金属表面处理]