摘要
为了解并掌握在役管道的内涂层性能及失效过程,保障下游用气质量和相关输气系统的安全,保证应用内涂层技术所带来的社会性和经济性.文中采用电化学交流阻抗技术研究了某干线服役近5年的天然气管道减阻内涂层在3.5%NaCl溶液中的电化学行为.结果表明:服役近5年后的环氧涂层由于存在一定量的孔道,使水分子很容易到达涂层/基底金属界面,经过了24 h浸泡后,涂层电阻从109Ω.cm2迅速降到小于106Ω.cm2.当涂层电阻降低到104Ω.cm2,涂层性能劣化,出现鼓泡,得出涂层的阻抗模型以及浸泡不同时间涂层的电容和电阻值.
Inorder to learn the internal coating performance and failure process,which is important to ensure the quality of transported gas,the safety of gas transmission system and the social and economic benefit of the internal coating,the electrochemical behavior of the inner coating of the pipeline in five-year service in 3.5% NaCl solution was studied by means of electrochemical impedance spectroscopy.The result indicated that,after five-year service,water molecules reached the coating/base metal interface through amount of channel in epoxy coating.After 24 h immersion the coating resistance dropped quickly to less than 106 Ω·cm2 from 109 Ω·cm2.When the coating resistance dropped to 104 Ω·cm2,coating performance degraded and bubbling appearance occured.The coating impedance model,capacitance and resistance value at different immersion stages were obtained.
出处
《西安工业大学学报》
CAS
2011年第3期251-256,共6页
Journal of Xi’an Technological University
关键词
在役管道
电化学阻抗谱
内涂层
防腐蚀性能
serviced pipeline
electrochemical impedance spectroscopy
internal coating
anticorrosion performance
