The Corrosion Behaviors of Bulk Nanocrystalline Ingot Iron in Mixed Solution with Sulfuric Acid and Sodium Sulfate

The electrochemical corrosion properties of bulk nanocrystalline ingot iron (BNII) produced by severe rolling technique and as-received conventional polycrystalline ingot iron (CPII) in.0.1 mol/L H2SO4 + 0.25 mol/L Na2SO4 solution were studied by potentiodynamic polarization, electrochemical impedance spectroscopy and scanning electron microscope at room temperature. The corrosion current density and capacitance of double electrode layer of BNII were one order of magnitude less than those of CPII respectively, the polarization resistance of BNII was one order of magnitude larger than that of CPII. These electrochemical corrosion results demonstrated that the corrosion resistance of BNII was enhanced in comparison with that of CPII in.0.1 mol/L H2SO4 + 0.25 mol/L Na2SO4 solution at room temperature. The enhanced corrosion resistance of BNII was attributed to the differences of valence electron configurations (work function, the density distribution of valence electrons and the binding energies of valence electrons) between BNII and CPII from electrochemical corrosion nature.