Cu-40Ni-20Cr合金在含Cl^-介质中的电化学腐蚀行为研究  

Studies on Electrochemical Corrosion Behavior of Cu-40Ni-20Cr Alloy in Cl^- Medium

作　　者：边静[1] 李凤春[1] 曹中秋[1] 

机构地区：[1]沈阳师范大学化学与生命科学学院,辽宁沈阳110034

出　　处：《沈阳师范大学学报（自然科学版）》2007年第1期68-71,共4页Journal of Shenyang Normal University:Natural Science Edition

基　　金：辽宁省教育厅基金资助项目(202112022)

摘　　要：利用动电位扫描法和交流阻抗技术研究了传统电弧熔炼制备的Cu-40Ni-20Cr合金在不同Cl-浓度的腐蚀介质中的电化学腐蚀行为.结果表明:合金在单一Na2SO4介质中具有较低的腐蚀电流,腐蚀速度较慢,腐蚀过程由电化学控制腐蚀,电化学阻抗谱呈单容抗弧特征.在含Cl-腐蚀介质中,随着Cl-浓度的增加,自腐蚀电位不同程度负移,腐蚀电流增大,腐蚀速度加快.Cl-浓度大于0.02 mol.L-1时,出现Warburg阻抗特征,腐蚀过程由电化学控制转为扩散控制;加入Cl-后,极化电阻减小,腐蚀过程中存在一定弥散效应.The electrochemical corrosion behavior of Cu-40Ni-20Cr alloy prepared by conventional casting in solution with different Cl^- concentrations has been investigated by means of potentialdynamic polarization method with Electrochemical Impedance Spectroscopy （EIS）. Results show that Cu-40Ni-20Cr alloy has smaller corrosion current and flower corrosion rate in single Na2SO4 medium. The process of corrosion is controlled by electrochemical reaction and the Nyquist plot is composed of single capacitance loop. While the corrosion potential moved toward negative direction in different degrees in Cl^- medium, the corrosion currents increased and corrosion rates become faster with increase of Cl^- concentration. There are Warburg impedances appeared in the Nyquist plots when the Cl^- concentrations are more than 0.02 mol·L^-1. The process of corrosion is controlled by diffusion. By adding Cl^- to Na2SO4 solution, resistances of polarization decreased and disperse effects occurred in the process of corrosion.

关 键 词：Cu-40Ni-20Cr合金 极化曲线 交流阻抗 腐蚀 

分 类 号：TG146.1[一般工业技术—材料科学与工程]