基于丝束电极的环氧涂层失效演变行为研究  

Study on Failure Evolution Behavior of Epoxy Coating Based on Beam Electrode Technology

作　　者：孙祥太 SUN Xiangtai(SINPEC Zhongyuan Oilfield,Puyang 457001,China)

机构地区：[1]中石化中原油田分公司,河南濮阳457001

出　　处：《电镀与精饰》2021年第4期25-29,共5页Plating & Finishing

摘　　要：本文采用丝束电极测试方法,结合图像表征,分析了腐蚀介质扩散引起的涂层失效过程和金属基体的腐蚀形貌特征。结果表明,涂层失效起始于失效位点,即水分子优先到达涂层/金属界面的位置,因此“大阴极、小阳极”腐蚀原电池和氧浓差电池的形成促进了金属基体点蚀的发展。当界面上电化学反应全面展开,腐蚀产物向涂层中扩散堵塞扩散通道,此时涂层体系电位大幅度负向偏移且保持稳定,并且涂层剥离。In this paper,the epoxy coating failure process and the corrosion morphology of metal matrix were analyzed using the method of beam electrode technology and image characterization.The results showed that the coating failure began at the failure point where the water molecules preferentially reach the coating/metal interface,so the formation of"large cathode,small anode"corrosion galvanic cell and oxygen concentration difference cell promoted the pitting corrosion characteristics of the metal matrix.When the electrochemical reaction was fully developed on the interface,the corrosion product diffused into the coating and blocked the diffusion channel,at this time,the coating system potential was significantly negatively shifted and remains stable,and the coating was stripped off.

关 键 词：丝束电极 环氧涂层 失效 点蚀 

分 类 号：TB31[一般工业技术—材料科学与工程]