400 kV/m高压直流电场对5052铝合金在NaCl溶液中干湿交替加速腐蚀行为的影响  

Effect of High DC Electric Field with 400 kV/m on Wet-dry Cyclic Accelerated Corrosion Behavior of 5052 Aluminum Alloy in NaCl Solution

作　　者：林德源 蔡振才 沈谢林 夏晓健 陈云翔 邵艳群[4] 郑跃胜[5] LIN Deyuan;CAI Zhencai;SHEN Xielin;XIA Xiaojian;CHEN Yunxiang;SHAO Yanqun;ZHENG Yuesheng(Electric Power Research Institute of State Grid Fujian Electric Power Co.,Ltd.,Fuzhou 350007,China;Sanming Power Supply Company of State Grid Fujian Electric Power Co.,Ltd.,Sanming 365000,China;Quanzhou Power Supply Company of State Grid Fujian Electric Power Co.,Ltd.,Quanzhou 362000,China;College of Materials Science&Engineering,Fuzhou University,Fuzhou 350116,China;College of Electrical Engineering and Automation,Fuzhou University,Fuzhou 350116,China)

机构地区：[1]国网福建省电力有限公司电力科学研究院,福建福州350007 [2]国网福建省电力有限公司三明供电公司,福建三明365000 [3]国网福建省电力有限公司泉州供电公司,福建泉州362000 [4]福州大学材料科学与工程学院,福建福州350116 [5]福州大学电气工程与自动化学院,福建福州350116

出　　处：《热加工工艺》2024年第23期141-146,共6页Hot Working Technology

基　　金：国家电网有限公司总部科技项目(52130417002K)。

摘　　要：沿海高温潮湿环境下高压直流电场对5052铝合金腐蚀行为的研究尚未见报导。在400 kV/m直流电场下,对5052铝合金进行干湿交替腐蚀试验,试验溶液为3.5wt%NaCl,12 h为一周期。使用扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、动电位极化曲线(LSV)、交流阻抗谱法(EIS)等评价直流电场对5052铝合金腐蚀形貌和腐蚀行为的影响。结果表明:在400 kV/m电场下,随着干湿交替时间延长,失重增加,失重速率减小,但失重速率均比无电场下相应时间的大。无电场时,先发生由阴极Al-Si和阳极Al构成的表面微电偶腐蚀,随后发生围绕Al-Si相的点蚀,直至出现较大腐蚀坑。Al-Si相促进了铝基体的纵深溶解。在电场作用下,腐蚀电位降低,腐蚀电流提高,钝化膜和基体构成大阴极-小阳极的电偶腐蚀,促进腐蚀。整个过程为钝化-钝化膜破裂-电偶腐蚀-剥落,与无电场的腐蚀有很大差异。The study of high voltage DC electric field on the corrosion behavior of 5052 aluminum alloy in coastal high temperature and humid environment has not been reported.The wet-dry cyclic corrosion tests of 5052 aluminum alloy under 400 kV/m DC electric field intensity was carried out,the solution was 3.5wt%NaCl and one cycle was 12 h.The effect of DC electric field on the corrosion morphology and corrosion behavior of 5052 aluminum alloy was evaluated by using SEM,EDS,XPS and electrochemical tests.The results show that with the increase of the wet-dry cyclic corrosion time at 400 kV/m DC electric field,the weight loss increases and the corrosion weight loss rate decreases.But the weight loss rate of the samples is bigger than that of the corresponding samples without electric field.Without electric field,the surface microelectric couple corrosion composed of the cathode Al-Si and the anode Al occurs first,then pitting around the Al-Si phase occurs until a large number of corrosion pits appear.The Al-Si phase promotes the dissolution of the Al matrix in depth direction.Under the action of the electric field,the corrosion potential decreases and the corrosion current increases,the passivation membrane and the matrix constitute the corrosion of large cathode-small anode,which promotes corrosion.The whole process is passivation-passivation film rupture-electrocouple corrosion-spalling,which is very different from the corrosion without electrical field.

关 键 词：铝合金 干湿交替腐蚀 高压直流电场 

分 类 号：TG172.5[金属学及工艺—金属表面处理]