纯Al表面局部孔蚀的电化学噪声特征分析

Electrochemical Noise Analysis of Local Pitting Corrosion Behavior of Pure Aluminum

利用电化学噪声技术监测纯Al在3.5%NaCl溶液中的局部孔蚀行为。通过电化学噪声的时域分析、频域分析以及形貌特征,对纯Al的腐蚀过程进行深入研究。结果表明:电化学噪声时域谱可以预测局部腐蚀的发生,定性地说明腐蚀发生的类型;电流标准偏差σI,噪声电阻Rn和电流白噪声水平W能表征腐蚀发展的剧烈程度,当腐蚀发生时,σI和W趋于增大,Rn趋于减小。

The local pitting corrosion behavior of the pure aluminum in 3.5% NaCl solution was characterized by electrochemical noise analysis technique. The corrosion processes for aluminum were studied in detail by analyzing time-domain and frequency-domain characteristics of electrochemical noise together with morphology features. The results show that the time-domain spectroscopy of the electrochemical noise can be used to predict the occurrence of local corrosion and qualitatively distinguish the type of corrosion. It was found that the current standard deviation σI, noise resistance Rnand current white noise levels W can reflect the corrosion intensity. When the corrosion occurs, σIand W tend to increase, but Rntends to decrease.