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采用动电位极化、交流阻抗(EIS)和电化学噪声(ECN)等电化学方法研究了304不锈钢微电极的腐蚀行为。实验结果表明:极限扩散电流密度与电极尺寸之间具有非线性关系,随着电极面积的减小,极限扩散电流密度增大,溶液阻抗减小,双电层电容增大,自腐蚀电位负移,腐蚀电流密度增大。电化学噪声谱表明,随着电极面积减小,亚稳态点蚀噪声峰的频度降低,亚稳态点蚀的发生存在一个临界尺寸。
The corrosion behavior of 304 stainless steel microelectrode was studied by electrochemical methods such as potentiodynamic polarization, alternating current impedance (EIS) and electrochemical noise (ECN). The experimental results show that there is a nonlinear relationship between the limit diffusion current density and the electrode size. As the electrode area decreases, the limit diffusion current density increases, the solution impedance decreases, the electric double layer capacitance increases, and the self-corrosion potential shifts negatively , Corrosion current density increases. The electrochemical noise spectrum shows that as the electrode area decreases, the frequency of metastable pitting noise peaks decreases and the critical size of metastable pitting exists.