316L不锈钢在不同pH值硼酸溶液中的电化学行为研究  

Electrochemical Behavior of 316L Stainless Steel in Borate Buffer Solution with Different pH

作　　者：王彦亮[1] 陈旭[1] 王际东[1] 宋博[1] 范东升[1] 何川[1] 

机构地区：[1]辽宁石油化工大学石油天然气工程学院,抚顺113001

出　　处：《中国腐蚀与防护学报》2017年第2期162-167,共6页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(51201009);辽宁省自然科学基金(2013020078)~~

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。The electrochemical characteristics of the passivation film formed on 316L stainless steel in borate buffer solutions with pH of 4, 7 and 11, respectively were characterized by means of potentiodynamic polarization, electrochemical impedance spectroscopy and Mott-Schottky technology. The composition of passive film was analysized by X-ray photoelectron spectroscopy （XPS）. The results showed that the stable passivation film could form on the steel surface in all the three borate buffer solutions. The passivation potential range decreased and the transpassive potential dropped significantly with the in- creasing pH value. The transpassive current of 316L stainless steel in alkaline borate buffer solution in- creased significantly. The integrity of the passive film was the best in the neutral solution, while it was the worst in the acid solution. The Mott-Schottky results showed that the semiconductor type of the passive film transferred from n-type to p-type with the increasing potential in acid solution. It was n-type and p- type semiconductor in the neutral and alkaline solution, respectively. It was attributed to that the chromi- um hydroxide dropped down and the formed iron compound was transformed from FeO（OH） to Fe304. The content of Cr203 was decreased in alkaline solution, which resulted in lower corrosion resistance.

关 键 词：316L不锈钢 PH值 钝化膜 电化学 XPS 

分 类 号：TG174[金属学及工艺—金属表面处理]