应用电化学扫描隧道显微技术，考察外加电位、介质条件及时间等因素对不锈钢发生微点腐蚀早期阶段表面形貌的影响，从纳米级空间分辨度进一步探索不锈钢表面钝化膜破坏及微点腐蚀发生早期过程机理．结果表明，不锈钢在点蚀早期阶段，首先发生不稳定微点腐蚀，其表面形貌随着不稳定微点腐蚀的发生、消长而变化．不稳定微点腐蚀的几何尺寸约为１０ｎｍ，极化电位愈正，不锈钢钝化膜局部溶解破坏和微点腐蚀发生的倾向性愈大，不稳定的微点腐蚀在一定的条件下可发展为稳定点腐蚀．即使在开路电位下，Ｃｌ－也可能在不锈钢表面呈不均匀分布，进而导致钝化膜的局部破坏 Electrochemical scanning tunneling microscopy was used to investigate the effect of applied potential, dielectric constant and time on the surface morphology of stainless steel in the early stage of micro-point corrosion. The nano-scale spatial resolution was used to further explore the damage and micro-point Corrosion occurs early process mechanism. The results show that in the early stage of pitting corrosion, stainless steel first instability micro-point corrosion, the surface morphology changes with the occurrence of unstable micro-point corrosion, growth and decline. The geometric size of the unstable micro-point corrosion is about 10 nm. The more the polarization potential is, the greater the tendency of local dissolution and micro-point corrosion of the stainless steel passivation film is. The unstable micro-point corrosion can be developed under certain conditions as Stable point corrosion. Even at open circuit potential, Cl- may be unevenly distributed on the stainless steel surface, which in turn may lead to localized damage to the passivation film