921A钢板腐蚀电场的Frumkin修正  

Frumkin Correction of Corrosion Electric Field Generated by 921A Steel

作　　者：徐庆林 王向军[1] 张建春[1] 刘德红 Xu Qinglin;Wang Xiangjun;Zhang Jianchun;Liu Dehong(College of Electrical Engineering Naval University of Engineering,Wuhan 430033,China;City College Wuhan University of Science and Technology,Wuhan 430083,China)

机构地区：[1]海军工程大学电气工程学院,武汉430033 [2]武汉科技大学城市学院,武汉430083

出　　处：《电工技术学报》2020年第14期2951-2958,共8页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金面上项目(41476153);武汉科技大学城市学院科学基金项目(2018CYZDKY002)资助。

摘　　要：为了研究不同质量分数氯化钠溶液中腐蚀电场的Frumkin修正效果,采用电化学阻抗谱测试得到921A钢电极在腐蚀电位下的双电层电容,并由此计算分散层电位的实验值,根据双电层的Stern模型,推导分散层电位与双电层电位、支持电解质质量分数的理论关系,并得到分散层电位的理论值。根据Frumkin修正理论,对阴极和阳极的电极过程动力学分别进行修正,得到与分散层电位相关的修正后的Tafel方程式。分别以修正前后的Tafel方程式作为921A钢板腐蚀电场边界元模型的边界条件,得到修正前后的腐蚀电场分布,并与实测腐蚀电场进行对比。结果表明,修正后的电场模量幅值与实验结果更为接近,说明在仿真过程中对Tafel边界条件进行修正是有必要的,当氯化钠溶液质量分数分别为1.5%、2.5%和3.5%时,修正效果分别为12.2%、10.8%和9.4%。In order to study the Frumkin correction effect of corrosion electric field in different concentrations of sodium chloride solution,the electric double layer(EDL)capacitance of 921A steel electrode at the corrosion potential was acquired by electrochemical impedance spectroscopy(EIS)Accordingly the experimental value of diffuse layer potential was calculated.The theoretical relationship between diffuse layer potential and potential of EDL and concentration of supporting electrolyte was derivedaccording to the Stern model of EDL.Therefore,the theoretical value of diffuse layer potential was obtained.According to the Frumkin correction theory,the electrode kinetics of cathode and anode were corrected respectively,and the modified Tafel equation related to diffuse layer potential was acquired.The uncorrected and corrected Tafel equation was used as the boundary condition of the boundary element model(BEM)of corrosion electric fieldfor 921A steel plate,so the corrosion electric field distributions before and after Frumkin correction were obtained and compared with the experimental results.The results show that the corrected amplitude of electric field modulus is closer to experimental values,indicating that it is necessary to correct the Tafel boundary condition during simulation process.Moreover,when the concentration of sodium chloride solution is 1.5%,2.5%and 3.5%,the correction effectis 12.2%,10.8%,and 9.4%,respectively.

关 键 词：腐蚀电场 Frumkin修正 双电层 分散层电位 921A钢 边界元法 

分 类 号：TM15[电气工程—电工理论与新技术]