直接空冷凝汽器3种可选材质的腐蚀性能  

Electrochemical study of three adaptive materials for air-cooled condensers duct

作　　者：朱志平[1] 肖剑峰[1] 乔越[1] 曹颉[1] 田龙标 

机构地区：[1]长沙理工大学化学与生物工程学院,湖南长沙410004

出　　处：《长沙理工大学学报（自然科学版）》2017年第1期84-91,共8页Journal of Changsha University of Science and Technology:Natural Science

基　　金：湖南省科技计划重点项目(2013GK2016);湖南省研究生科研创新项目(CX2016B415)

摘　　要：火电厂直接空冷凝汽器因特殊介质环境和20~#碳钢(20~#)的易腐蚀性导致管材腐蚀特别严重。针对这一问题,自建了一套空冷凝汽器模拟装置,选取3004铝合金(3004)和304不锈钢(304)为20#的替换材质,对3种材质进行了腐蚀特性研究,包括模拟挂片腐蚀速率、电化学极化曲线和电化学交流阻抗(EIS)测试等,分析了介质温度、溶解氧和pH值对3种材质腐蚀特性的影响,比较了3种材质的腐蚀性能。研究结果表明,3004和304的腐蚀速率比20~#小1~2个数量级,3004具有非常好的阻抗特性,304次之,20~#阻抗特性较差;304出现了Warburg阻抗,电极反应属于混合控制;温度和溶解氧对3004和304腐蚀性能的影响要比20#小。从技术经济角度上看,3004具有较好的应用前景。The corrosion within direct air cooled condenser duct in power plant is particularly serious, due to the bad gas-liquid environment and the ease of corrosion of 20# carbon steel （20# ）. In this paper, 3004 aluminum alloy（3004） and 304 stainless steel（304） is adaptive to instead of 203 . Study on corrosion of three materials was carried in a self-made device simulating actual operation environment of ACC, including hanging piece simulating corrosion, polarization curve and Electrochemical impedance spectroscopy（EIS）. It was to analyze the influence of the fluid temperature, dissolved oxygen and pH on the corrosion of three material and compare the corrosion resistance of three materials. The results show that the corrosion rate of 20# is more than 10-1 000 times that of 3004 and 304. The performance of resistance scale on the 3004 is better than that on the 20e and 304, and 304 is better than 20# . EIS of 304 has the Warburg impedance. Electrode reactions are mixed control, the flu- id temperature and dissolved oxygen have much influence on the 20# over 3004 and 304. 3004 has a better application prospect in techno-economical analysis.

关 键 词：20#碳钢 3004铝合金 304不锈钢 直接空冷凝汽器 极化曲线 交流阻抗 

分 类 号：TG174.43[金属学及工艺—金属表面处理]