腐蚀电化学中的频谱分析研究

STUDIES ON THE SPECTRAL ANALYSES IN THE ELECTROCHEMISTRY OF CORROSION

简要介绍了我们实验室中进行的电化学阻抗频谱(EIS)与孔蚀诱导期中电化学噪声(EN)的谱功率密度(SPD)的研究进展。通过引入定态过程稳定性条件,导出了具有2和3个时间常数EIS的法拉第导纳公式,将它们应用于EIS数据分析的工作也正在进行中;发展了混合电位下的EIS理论并成功地应用于界面型缓蚀剂研究。证明了孔蚀诱导期中EN的SPD的特征是:极低频率下为“白噪声”,在较高频率下则转变为f^n噪声,n的数值在2至4之间。导出了相应的理论公式。

Researches carried out in our laboratory on electrochemical impedance spectrum (EIS) and on the spectral power density (SPD) of the electrochemical noise (EN) during the incubation stage of pitting corrosion are introduced briefly. By introducing the stability conditions of steady state, equations of the faradaic admittance for EIS with 2 and 3 time constants were deduced, and the work on the application of the equations in EIS data analysis is underway. A theory on EIS at mixed potential was developed and was successfully applied in the investigations on interface inhibitors. The features of the SPD of the EN during the incubation stage of pitting corrosion were found to be independent of frequency f as so-called 'white noise' at very low frequencies and f' noise in higher frequency range. The value of n was found to be within 2 to 4. An equation of SPD in accord with the experimental data was deduced theoretically.