交流干扰与阴极保护共同作用对X65管线钢的腐蚀行为研究

Corrosion Behavior of X65 Steel by AC Interference and Cathodic Protection

基于自行设计搭建杂散电流腐蚀实验装置,结合电化学测试和失重实验对交流杂散电流和阴极保护作用下的管线钢腐蚀行为开展研究。结果表明:随着交流电流密度的增大,管线钢腐蚀电位负向偏移,增加了金属腐蚀的倾向性。交流干扰促进了交流电正半周期内的阳极氧化反应,管线钢腐蚀速率增大。交流频率的增加缩短了交流电正半周期管线钢发生腐蚀的时间,减小了促进金属氧化反应的法拉第电流,管线钢腐蚀速率减小。而在强酸和强碱环境下,管线钢的腐蚀速率均增强。

The corrosion behavior of pipeline steel under the combined action of the applied alternating stray current and cathodic protection was assessed via a home-made stray current corrosion testing device,mass loss measurement and electrochemical methods.The results show that with the increase of AC current density,the corrosion potential of pipeline steel is negatively shifted and the metal corrosion tendency is enhanced.AC interference promotes the anodic oxidation reaction in the positive half cycle of AC and then increases the corrosion rate of pipeline steel.With the increase of AC frequency,the corrosion process of the pipeline steel is shortened for each cycle of AC,the Faraday current,as promoter for metal oxidation reaction is suppressed,therewith the corrosion rate of pipeline steel is reduced.The corrosion rate of pipeline steel increases in strong acid or alkali environment.