摘要
采用动电位扫描、电化学阻抗谱和电化学噪声等方法研究了4种不同表面粗糙度304不锈钢电极在质量分数为3%的NaCl溶液中的早期腐蚀行为。随着不锈钢电极表面粗糙度的下降,304不锈钢自腐蚀电位与点蚀电位均有所上升;电荷转移电阻噪声电阻明显升高,而电位标准偏差与电流标准偏差则有所降低;粗糙度0.25μm的电极在阻抗谱低频区出现45°扩散尾,表明钝化膜表面开始发生扩散过程。研究结果表明:与粗糙的不锈钢表面相比,在光滑的不锈钢表面上亚稳态蚀点的产生与生长更加难以进行。
In 3% NaCl solution, the early stages of pitting corrosion of 304 stainless steel ground with different aluminum oxide water proof papers were studied by dynamic potential scanning, electrochemical impedance spectrum （EIS） method and electrochemical noise （EN） method. The results indicate that, with the decrease of surface roughness, the corrosion potential and pitting corrosion potential rose, the charge transfer resistance and the noise resistanc also rose obviously. The standard deviation of potential, as well as the standard deviation of current, decreased as the surface roughness decreased. A diffusion tail inclining along the angle of 45° to the x-axis was observed when the electrode with 0.25μm roughness was tested, indicating diffusion began at the surface. The results suggest that metastable pits initiate and grow up more difficultly at smooth surface than at rough surface.
出处
《失效分析与预防》
2012年第2期86-90,共5页
Failure Analysis and Prevention
基金
国家自然科学基金(57071083)
