摘要
采用极化曲线、电化学阻抗谱(EIS)、莫特-肖脱基曲线和X射线光电子能谱(XPS)研究了MoO42-和NO2-对碳钢小孔腐蚀的协同抑制作用。结果表明,MoO42-和NO2-联合应用使碳钢的亚稳态孔蚀电位(Em)和孔蚀击穿电位(Eb)发生明显正移,并且显著提高了两者的差值,对抑制亚稳态小孔形核以及亚稳态小孔向稳态小孔转变的效果明显;MoO42-和NO2-联合应用可以在碳钢表面形成一层Fe2O3+Fe2(MoO4)3复合钝化膜,这层复合钝化膜的阻抗较大、缺陷较少,对碳钢的保护作用明显加强。
The synergistic inhibition effect of MoO42-and NO2-on pitting corrosion of mild steel was studied by polarization curve, electrochemical impedance spectroscopy（EIS）, Mott-Schottky plot, and X-ray photoelectron spectroscopy（XPS）. The results showed that the metastable pitting potential（Em） and the pitting breakdown potential（Eb） of the mild steel shift significantly to much positive and the value of（Eb-Em） increased markedly when MoO42-and NO2-were applied at the same time, indicating that the combined application of MoO42-and NO2-not only restrained the initiation of metastable pits but also prevented the transition from metastable pits to stable pits, correspondingly where a composite passive film Fe2O3＋Fe2（MoO4）3could form on the mild steel surface.The impedance of the composite passive film Fe2O3＋Fe2（Mo O4）3formed in the solution containing MoO42-and NO2-was larger than that of the single passive films formed in the solutions with individual MoO42-or NO2-, while the defects of the former was less than that of the later one, therefore,the composite passive film could provide better protectiveness for the mild steel.
出处
《腐蚀科学与防护技术》
CAS
CSCD
北大核心
2015年第4期321-326,共6页
Corrosion Science and Protection Technology
基金
国家自然科学基金项目(51171014和51210001)资助
