Abstract
The electrochemical corrosion properties of bulk nanocrystalline 304 stainless steel produced by severe rolling technique and its conventional polycrystalline 304 stainless steel were studied by immersion test for 20 days in 0.5 mol/L HCl solution at room temperature. The corrosion rate of bulk nanocrystalline 304 stainless steel was less than that of conventional polycrystalline 304 stainless steel. The electronic structures and compositions of the two oxide films on bulk nanocrystalline 304 stainless steel and conventional polycrystalline 304 stainless steel in 0.5 mol/L HCl solution for 20 days’ immersion at room temperature were also studied by X-Ray Photoelectron Spectroscopy (XPS). The pitting corrosion resistance of bulk nanocrystalline 304 stainless steel was also simultaneously enhanced in comparison to conventional polycrystalline 304 stainless steel. These results were attributed to the better chemically stable, more compact and thicker oxide film on bulk nanocrystalline 304 stainless steel. The better chemical stability of oxide film on bulk nanocrystalline 304 stainless steel was due to the larger binding energies of Fe3+2p3/2, Fe2+2p3/2 and Cr3+2p3/2 in the oxide film on bulk nanocrystalline 304 stainless steel.
Keywords: Electronic structures, oxide film, pitting corrosion, stainless steel, X-Ray photoelectron spectroscopy.
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