金属管道交流腐蚀研究新进展

交流腐蚀对金属管道的危害不容忽视，交流电不仅可以通过杂散电流的形式对金属管道造成腐蚀危害，还可以通过感应使金属管道中产生交流电流，形成交流干扰破坏。分别从交流腐蚀的实验研究、理论分析及腐蚀机理角度，对近年来国内外开展的交流腐蚀研究进行系统综述。实验证明交流电不仅能加速金属的腐蚀，破坏金属表面的钝化膜，诱发点蚀，还能造成阴极保护系统的阴极保护电流激增，保护电位严重波动，甚至引起牺牲阳极极性逆转等危害。交流腐蚀的机理十分复杂，人们试图通过理论分析和实验归纳对这一复杂行为进行解释，形成了几类较为典型的腐蚀机理假说。虽然交流腐蚀的研究已有百年的历史，但仍存在许多难点问题亟待解决，通过对目前研究中存在的重点问题进行探讨，展望这一领域的研究前景及发展趋势，为相关领域的研究人员提供新思路。

New progress in studying alternating current corrosion on metal pipelines

A damage caused by alternating current (AC) corrosion on buried metal pipelines can not be ignored because alternating current may not only result in corrosion on metal pipelines through stray current but also generate an alternating electric current within metal pipelines by induction, which creates alternating current interference. Moreover, risks of AC corrosion or overprotection on buried metal pipelines are increasing with the increase of laying coated pipelines in proximity to AC powered rail transit systems or high voltage AC power transmission lines. Here we made a systematic review on AC corrosion researches of recent years in terms of the experimental study, theoretical analysis and corrosion mechanism, respectively. It is generally believed that a higher alternating current could lead to a higher risk of AC corrosion. The results of laboratory experiments on the influence of AC interference show that an alternating electric current can not only accelerate metal corrosion, destroy the passive film and induce pitting corrosion, but also interfere with the normal operation of a cathodic protection system due to a sharp increase of the cathodic protection current, a severe disturbance of the protection potential and even an anodic polarity reversal. Mechanisms of AC corrosion are very complex and people have made great attempts to explain these complicated processes through theoretical analyses and experimental simulations. There are only a few typical hypotheses on mechanisms of AC corrosion proposed so far and many difficult problems remain to be unsolved though studies on AC corrosion may date back to the late 19th century. In addition, we discussed some key problems of AC corrosion in details, predicted the research prospect and development trend of this frontier, which may be a help to researchers involved in the related domains.