无溶剂环氧防腐涂层在不同流速模拟海水冲刷条件下的失效行为  

Degradation Behavior of Solvent-free Epoxy Coatings in Simulated Flowing Sea Water with Sand by Different Flow Rates

作　　者：赵洪涛[1] 陆卫中[1] 李京[1] 郑玉贵[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016

出　　处：《中国腐蚀与防护学报》2017年第4期329-340,共12页Journal of Chinese Society For Corrosion and Protection

基　　金：中国科学院A类战略性先导科技专项(XDA13040500)~~

摘　　要：通过OCP和EIS对3种无溶剂环氧防腐涂层在60℃不同流速(2,4和6 m/s)下,含1%(质量分数)石英砂的模拟海水环境中的失效行为进行了研究,并利用CLSM观察了冲刷后涂层的表面形貌,利用SEM和EDS对涂层底部Q345E钢表面的腐蚀产物进行了分析,探讨了无溶剂环氧防腐涂层在模拟海水冲刷条件下的失效机理。结果表明,冲刷条件下,3种涂层的失效过程大大缩短,流速对水在涂层中的传输速率影响不明显,涂层加速失效的原因主要有两点:一方面,砂粒对涂层的磨损作用导致涂层表面产生凹坑或孔洞,缩短了腐蚀介质扩散到达涂层/金属界面的距离;另一方面,流速加速了Cl-在涂层中的传输从而使涂层失效加速。The degradation behavior of three solvent-free epoxy coatings on carbon steel Q345 E in simulated flowing sea water with 1%（mass fraction） sand by different flow velocities（2, 4 and 6 m/s respectively） was investigated at 60 ℃ by means of open circuit potential（OCP） measurement and electrochemical impedance spectroscopy（EIS） as well as confocal laser scanning microscopy（CLSM） and scanning electron microscopy（SEM） with energy dispersive spectrometer（EDS）. Results showed that the failure process of the three coatings was greatly shortened in the flowing slurry, and the reason for the accelerated degradation of the coatings may be ascribed to the facts that： on one hand, the wear effect of sends, which led to the generation and development of pits or holes on/in coatings which shorten the diffusion path of the corrosive medium from the outside environment to the coating/metal interface, on the other hand, the high flow rate of the slurry could accelerate the transmission of Cl-to the coating.

关 键 词：无溶剂环氧防腐涂层 海水冲刷 流速 失效 

分 类 号：TG174.5[金属学及工艺—金属表面处理]