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埋地金属管道交流干扰腐蚀行为研究 许立宁1) 徐欣1) 余和初2) 1) 路民旭1)1) 北京科技大学新材料技术研究院腐蚀与防护中心,北京,100083 2) 北京声迅电子股份有限公司,北京, 100085 摘 要 建立了埋地金属管道交流干扰腐蚀模拟实验装置，研究了交流电流密度对交流腐蚀行为的影响。利用失重法测试了腐蚀速率，用体式显微镜观察了试样表面腐蚀产物的沉积，用扫描电镜观察了腐蚀产物的微观形貌，并监测了交流电流随时间的变化。结果表明，利用电阻耦合的方式施加交流干扰，腐蚀的严重程度与交流电流密度直接相关；如果不对交流电源的输出进行调节，交流电流密度会随着致密腐蚀产物的沉积而显著降低；腐蚀产物特性对交流腐蚀严重程度有较大影响。 关键词 埋地金属管道，交流干扰腐蚀，腐蚀产物，电流密度 中图法分类号 TG172.9 文献标识码 A The Study on AC Interference Corrosion of Buried Metal Pipeline Xin Xu1), Lining Xu1)*, Hechu Yu 2), Minxu Lu1) 1) Corrosion and Protection Center, Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 2) Beijing Telesound electronics Co.,Ltd., Beijing 100085 ABSTRACT The simulation test fitting of AC interference corrosion on buried metal pipelines was established, and the influence of AC current density on corrosion behavior was studied. The velocity of AC interference corrosion was calculated by weight loss method. The deposition of corrosion production on the steel surface was observed and the microscopic morphology of corrosion production was observed by Scanning Electron Microscope. The AC current of different test periods were monitored. The results show that, if the AC interference is applied by resistance coupling method, the severity of AC interference corrosion will be directly related to the AC current. And if the output of AC power supply is not adjusted during the test, the AC current will decrease with the deposition of dense corrosion product. The character of corrosion product has a great influence on AC interference corrosion. KEY WORDS buried metal pipeline, AC interference corrosion, corrosion product, current density 随着全球经济的快速发展，能源需求日益旺盛，输送石油或天然气的埋地管道也加速建设。埋地金属管道如果与高压交流输电线路等电力设施并行建设，可能遭受交流干扰而发生严重腐蚀[1]，国内外已发生多起管道泄露事故。1991年，加拿大的Kitchener市发现输气埋地管道受间隔14m远的高压线影响，交流干扰电压达8V，运行四年后出现腐蚀失效[2]。交流干扰腐蚀已成为腐蚀研究领域的热点，每年有大量文献报道。早期实验研究集中于交流电位或电流极化对金属腐蚀速率的影响上，普遍认为随着交流峰值电压的增大，腐蚀速率加快[3]。后来研究发现，交流腐蚀速率并不直接受交流电压的影响，起主要作用的是交流电频率和交流电流密度[4