摘要
用电化学阻抗谱(EIS)方法研究了固溶态、敏化态304不锈钢在0.5mol/L H2SO4+0.01mol/L KSCN溶液中的阻抗谱特征.研究表明,不锈钢在不同极化电位下的阻抗谱呈现活性溶解、活化-钝化、钝化及再活化的特征.达到再活化之前,固溶态和敏化态的不锈钢在0.5mol/L H2SO4+0.01mol/L KSCN溶液中呈现相同的EIS特征;而在再活化区,钝化膜局部溶解,EIS图有两个容抗弧,低频容抗弧延伸到第二象限,呈现负电阻特征,低频下敏化态比固溶态不锈钢阻抗模值小一个数量级.
Electrochemical impedance spectroscopy （EIS） measurements were performed on sensitized and solutioned 304 stainless steels respectively in the process of Electrochemical potentiodynamic reactivation （EPR） polarization in 0.5molfL H2SO4 ＋0.01molfL KSCN solution. The variation rules of impedance resistance in process of EPR polarization were analyzed. It was found that the EIS spectra of the stainless steels during EPR polarization ex- hibited features of active dissolution, activation - passivation, passivation and reactivation. Before reactivation, the two kinds of stainless steels had the same EIS characteristics. In the reactivating region the passivated film dissolved partially and the impedance modulus of the sensitized stainless steel was one magnitude order smaller than that of the solution - treated stainless steel, indicating that intergranular corrosion had occurred on the surface of the sensitized stainless steel. In addition two capacitive loops appeared in the EIS of the sensitized stainless steel and it was quite interesting that the second arc at the low frequency range was actually a negative resistance capacitive loop. These results may provide essential basis for detecting intergranular corrosion susceptibility of stainless steel by electrochemical impedance spectroscopy.
出处
《中国腐蚀与防护学报》
CAS
CSCD
北大核心
2007年第2期74-79,共6页
Journal of Chinese Society For Corrosion and Protection
基金
国家自然科学基金重大项目资助(50499335)
关键词
不锈钢
晶间腐蚀
电化学阻抗谱
stainless steel, intergranular corrosion, electrochemical impedance spectroscopy
作者简介
秦丽雁，女，1965年生，博士生，研究方向为腐蚀电化学
