目的 研究在0.1 mol/L NaCl硼酸缓冲溶液中，研究HCO3–对超级13Cr马氏体不锈钢的钝化及点蚀行为的影响。方法 采用动电位极化、恒电位极化、Mott-Schottky曲线、电化学阻抗谱等电化学测试手段，并结合3D超景深显微镜进行点蚀形貌观察，研究超级13Cr马氏体不锈钢的电化学腐蚀行为。结果 随着HCO3–浓度的增加，超级13Cr的钝化区间变宽，点蚀电位向正向移动，稳态点蚀发生的敏感性降低。HCO3–减少了超级13Cr亚稳态点蚀数量，降低了亚稳态点蚀电流密度峰值的平均值。随着HCO3–浓度的增大，超级13Cr钝化膜电阻Rf升高，电荷转移电阻Rct升高，钝化膜电容Cf逐渐减小。HCO3–使得超级13Cr钝化膜半导体特性由n型转变为n+p型双极性，且随着溶液中HCO3–浓度的增大，钝化膜中的施主密度ND和受主密度NA减小。结论 HCO3–的加入使得超级13Cr不锈钢钝化膜厚度增大，钝化膜内点缺陷密度降低，对基体的保护作用增强，抑制了超级13Cr的亚稳态和稳态点蚀发生。

The work aims to investigate the influence of HCO3ˉ on the passivation and pitting behavior of super 13Cr mar-tensitic stainless steel in 0.1 mol/L NaCl containing borate acid buffer solution. Potentiodynamic and potentiostatic polarization tests, Mott-Schottky analysis and electrochemical impedance spectroscopy measurements were adopted to observe the pitting morphology and study the electrochemical corrosion behavior of super 13Cr martensitic stainless steel in combination with 3D ultra-depth-of-field microscope. The passive region of super 13Cr was enlarged with the increase of HCO3ˉ concentration, thus contributing to more positive pitting potential and decreasing the sensitivity of stable pitting. HCO3ˉ reduced the metastable pitting of super 13Cr and reduced the average value of peak current density of metastable pitting. With the increase of HCO3ˉ concentration, the passivation film resistance Rf and the charge transfer resistance Rct of super 13Cr increased, but the passivation film capacitance Cf decreased. The presence of HCO3ˉ changed the semiconductivity of the passive film from n-type to n+p type and the donor density ND and acceptor density NA in passivation film decreased with the increase of HCO3ˉ concentration. The addition of HCO3ˉ effectively thickens the passive film of super 13Cr stainless steel and lowers the density of point defects in the passive film, which thereby enhances the protective effect of the passive film on the steel matrix and inhibits the occurrence of metastable and stable pitting corrosion of super 13Cr.