交流电对Q235钢腐蚀电位的影响规律研究

EFFECT OF AC CURRENT ON CORROSION POTENTIAL OF Q235 STEEL

利用室内模拟实验研究了交流电密度、电解质组分以及交流电频率对Q235钢腐蚀电位的影响规律.研究结果表明,交流电会使Q235钢腐蚀电位发生正向或负向偏移,偏移方向与Q235钢在不同电解质中阴、阳极极化速率有一定的相关性;偏移量随交流电密度增大而增大,随交流电频率增大而减小.结合金属界面双电层模型和腐蚀产物分析,对交流电引起Q235钢腐蚀电位偏移的机理进行了探讨.

With the rapid development of electricity,petroleum and transport industry,more and more pipelines are buried in parallel with high-voltage transmission lines or electrified railways, and the resulting AC corrosion phenomenon has attracted more attentions.In this work,the effects of AC current density,electrolyte composition and AC current frequency on corrosion potential of Q235 steel were studied through simulation experiments,and the results are as follows：AC current makes corrosion potential of Q235 steel deviate positively or negatively depending on polarization rate of anode/cathode within different electrolytes,and the offset of corrosion potential becomes more significant as the AC current density increases or the AC current frequency decreases.Besides,the inherent mechanism of such offset induced by AC current was also studied through double layer model of interface and corrosion products analyses.