承载作用下铁红环氧脂底漆失效过程的电化学响应特征

Characteristics of Electrochemical Impedance Spectroscopy in Deterioration Process of Iron Red Epoxy Primer under the Action of Load

采用局部电化学阻抗(LEIS)技术和电化学阻抗(EIS)技术研究了不同承载条件下,海水介质中铁红环氧脂底漆失效过程的电化学响应特征。结果表明:在不同的承载力作用下,铁红环氧脂底漆的失效过程呈阶段性变化,且应力加载过程加速了涂层的失效。在300 MPa屈服应力作用下,腐蚀介质可以沿着细小的裂缝快速渗透涂层,与基体接触,缩短涂层的失效时间。涂层失效后,整体阻抗值明显降低,同时试样表面随机分布的高阻抗点数量有所减少,涂层防护性能明显下降,基材发生腐蚀。

The failure behavior of iron red epoxy primer in seawater and with different loads was studied by EIS and LEIS.The results show that the degradation process of the iron red epoxy primer was periodic under the action of load,and the failure of the coat was speeded up by stress.The corrosion medium penetrated into the coating along tiny cracks,and could be in contact with the substrate,which shortened the deterioration time of coating,in yield stress of 300 MPa.At the same time,the random distribution of high impedance point number on the coating surface decreased,the protective performance of coating decreased,corrosion occured on the base metal.