316L不锈钢在不同pH值硼酸溶液中的电化学行为研究

发布时间：2018-06-24 01:11

本文选题：L不锈钢 + pH值　；参考：《中国腐蚀与防护学报》2017年02期

【摘要】：采用动电位极化、电化学阻抗及Mott-Schottky技术研究了316L不锈钢在pH值分别为4,7和11的硼酸溶液中钝化膜的电化学行为,并对钝化膜成分进行了X射线光电子能谱分析。结果表明:316L不锈钢在酸性、中性和碱性硼酸溶液中均能形成稳定的钝化膜,且随p H值增加钝化电位区间减小,过钝电位显著下降。碱性硼酸溶液中316L不锈钢过钝电流显著增加。钝化膜完整性在中性硼酸溶液中最好,酸性溶液中最差。MottSchottky曲线结果表明,在酸性环境中随着电位的升高,钝化膜由n型向p型转变;在中性和碱性环境中,钝化膜半导体类型分别为n型和p型。这是由于随p H值增加,Cr的氢氧化物消失,钝化膜中Fe由Fe O(OH)转变为Fe_3O_4;在碱性环境下钝化膜中Cr_2O_3含量减少导致耐蚀性下降。
[Abstract]:The electrochemical behavior of 316L stainless steel passivation film in boric acid solution with pH value of 4 ~ 7 and 11 was studied by potentiodynamic polarization, electrochemical impedance and Mott-Schottky technique. The composition of the passivation film was analyzed by X-ray photoelectron spectroscopy (XPS). The results show that the stable passivation film can be formed in acid, neutral and alkaline boric acid solution, and the range of passivation potential decreases with the increase of pH value, and the over-blunt potential decreases significantly. In alkaline boric acid solution, the overdull current of 316L stainless steel increased significantly. The integrity of passivation film was the best in neutral boric acid solution, and the worst in acid solution. The results showed that the passivation film changed from n-type to p-type in acidic environment with the increase of potential, and in neutral and alkaline environment, the passivation film changed from n-type to p-type in neutral and alkaline environment. The type of passivation film semiconductor is n type and p type respectively. This is because with the increase of pH value, the hydroxides of Cr disappear, the Fe in the passivated film changes from Feo (OH) to Fe3O _ 4, and the corrosion resistance decreases due to the decrease of Cr _ 2O _ 3 content in the passivated film in alkaline environment.
【作者单位】：辽宁石油化工大学石油天然气工程学院;
【基金】：国家自然科学基金(51201009) 辽宁省自然科学基金(2013020078)~~
【分类号】：TG174.36

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