醇酸清漆保护性的电化学加速评价  

Electrochemically Accelerated Evaluation of Protectiveness for an Alkyd Varnish Coating

作　　者：桂琪 郑大江[1] 宋光铃 GUI Qi;ZHENG Dajiang;SONG Guangling(Center for Marine Materials Corrosion ＆ Protection,College of Materials,Xiamen University,Xiamen 361005,China)

机构地区：[1]厦门大学材料学院海洋材料腐蚀防护中心,厦门361005

出　　处：《中国腐蚀与防护学报》2018年第3期274-282,共9页Journal of Chinese Society For Corrosion and Protection

基　　金：国家重点研发计划(2017YFB0702100)~~

摘　　要：将目前一种电化学阻抗谱和负电位极化相结合的AC/DC/AC技术拓展成正电位阳极极化加速与电化学阻抗评价相结合的技术,并用醇酸清漆/碳钢体系验证了该技术确实能加速涂层/金属体系的腐蚀破坏、快速评价涂层的保护性,不仅适用于阴极保护条件下的涂层,也可用于自然腐蚀甚至被阳极极化的体系。通过实验分析了该技术测得的阻抗数据及样品表面形貌的变化,研究了其加速破坏的机理,建立了涂层加速破坏失效的物理模型。对比浸泡实验、AC/阴极DC/AC循环加速实验及AC/阳极DC/AC循环加速实验阻抗变化规律和腐蚀破坏形貌。结果表明:结合阴极极化和阳极极化将是未来获得一种既快速又合理的有机涂层性能评价技术的途径之一。High corrosion resistant organic coatings are widely used for various industrial applications. These coatings normally have service life as long as tens of years. It is of great scientific interest and engineering significance to rapidly evaluate and compare the corrosion resistance of different longlife organic coatings. Different from the negative DC voltage used in the published AC/DC/AC（alternating current/direct current/alternating current） cyclic method to cathodically polarize an organic coating system before AC electrochemical impedance spectrum（EIS） in each cycle, a positive voltage was employed in this paper for the DC polarization in the AC/DC/AC cycling. The modified AC/DC/AC technique proved to be able to accelerate the damage of an alkyd varnish coating on carbon steel and thus quickly evaluate the coating corrosion resistance. Based on the measured impedance spectra and the recorded surface morphologic changes, the acceleration processes involved in the coating corrosion damage were analyzed, and a physical model for the accelerated failure of the coating/metal system was proposed. Based on the experiment results of electrochemical impedance spectroscopy and corrosion morphology from the immersion test, AC/cathodic DC/AC cyclic accelerated test, and AC/anodic DC/AC cyclic accelerated test, it shows that the evaluation method with the combination of cathodic and anodic polarization will be one of the effective and reasonable methods to evaluate the performance of organic coatings.

关 键 词：有机涂层 电化学阻抗 加速破坏 阴极极化 阳极极化 

分 类 号：TG174.46[金属学及工艺—金属表面处理]