中文摘要：

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MoO4^2-和NO^2-对碳钢小孔腐蚀的协同抑制作用。结果表明,MoO4^2-和NO^2-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;MoO4^2-和NO^2-联合应用可以在碳钢表面形成一层Fe2O^3＋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。

英文摘要：

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.