中文摘要：

借助动电位极化和电化学阻抗谱（EIS）测量，研究块体纳米晶工业纯铁（BNII）和粗晶工业纯铁（CPII）在室温0．4mol／LHCl溶液中的电化学腐蚀行为；用扫描电子显微镜（SEM）观察腐蚀后的表面形貌．结果表明，与CPII相比，BNII的自腐蚀电位Ecorr正向移动43mV，自腐蚀电流Icorr由68．37pA·cm^-2减小为29．55pA·cm^-2；电荷转移电阻Rt由427．0Q·cm^2增大到890．1Q·cm^-2两种材料发生的点蚀呈不同的形态：BNII的点蚀Ykd,而浅，腐蚀深度比较均匀，而CPII的腐蚀表面形成的点蚀孔深且孔径较大．与CPII相比，BNII在HCl溶液中的耐腐蚀性能明显提高．

英文摘要：

The electrochemical corrosion behavior of bulk nanocrystalline ingot iron （BNII） with grain size 38.9-87.5 nm and conventional polycrystalline ingot iron （CPII） with a mean grain size 50 μm in 0.4 mol/L hydrochloric acid solution is investigated by potentiodynamic polarization and electrochemical impedance spectroscopy （EIS） measurements at ambient temperature. The results show that Ecorr （open circuit corrosion potential） of BNII is 43 mV more positive than that of CPII. The Icorr （corrosion current density） decreases from 68.37 μA.cm-2of CPII down to 29.55μA.cm-2of BNII. The charge transfer resistance, Rt increases from 427.0 Ω.cm2 of CPII up to 890.1 Ω.cm2 of BNII. The scanning electrode microscopy （SEM） observation shows that pitting scarcely presented on bulk nanocrystalline ingot iron. Therefore the corrosion resistance of bulk nanocrystalline ingot iron is improved in comparison with the conventional polycrystalline ingot iron in hydrochloric acid solution.