成膜电位对S22053不锈钢在FeCl3溶液中钝化膜性能的影响

摘要

应用阳极极化、恒电位成膜极化、电化学阻抗谱以及Mott-Schottky测试等方法研究了在质量分数6％FeCl3溶液中S22053不锈钢表面钝化膜的性能.结果表明:S22053不锈钢的成膜电位在0.3～0.9V;当成膜电位在0.3～0.8V时, 随成膜电位的增加阻抗最大模值增大, 钝化膜稳定性增强, 当成膜电位在0.8～0.9V时则相反;在不同成膜电位极化30min成膜后, 钝化膜在扫描电位0～0.6V范围内均呈n型半导体特征, 在0.6～0.9V范围内呈p型半导体特征;由电化学阻抗谱测试得到的钝化膜厚度和由Mott-Schottky曲线得到的空间电荷层厚度随成膜电位的变化趋势一致, 二者均在成膜电位0.8V时出现峰值.%Passivation film performance on surface of S22053 stainless steel in 6 wt％ FeCl3 solution was studied by methods such as anodic polarization, constant potential film formation polarization, electrochemical impedance spectroscopy and Mott-Schottky test.The results show that the film formation potential of S22053 stainless teel was between 0.3-0.9 V.The maximum module value of impedance increased with increasing film formation potential in the range of 0.3-0.8 V, indicating that the stability of the passivation film was enhanced;in the range of 0.8-0.9 V, the opposite was true.The passivation films, formed after polarization at different film formation potentials for 30 min, showed an n-type semiconductor characteristic in the scanning potential range of0-0.6 V, and a p-type semiconductor characteristic in the range of 0.6-0.9 V.The change of the passivation film thickness with the film formation potential obtained by electrochemical impedance spectroscopy was consistent with the change of the space charge layer thickness with the film formation potential obtained by Mott-Schottky curves;both reached peak values at film formation potential of 0.8 V.