Corrosion resistance of SUS304 stainless steel after electrolytic treatment with aqueous solution containing fluorine and the analysis of passive film
The corrosion resistance of SUS304 stainless steel before and after electrolytic treatment with aqueous solutions containing fluorine was investigated and the FE-TEM, XPS and TOF-SIMS analyses were conducted to the passive film. The corrosion resistance of the steel in acidic 6.0％ FeCl3 solution was enhanced to more than twice by the electrolytic treatment, and the pitting potential of 2B surface in 1.0 M NaCl solution increased from 283 mV to 363 mV (vs. SSE). The enhancement is likely related to the formation of a stable, dense and uniform passive film, which should be attributed to the enrichment of chromium and the formation of stable chromium fluoride in the passive film, the removal of impurities and inclusions, and the suppression of specific adsorption of chloride ions due to the electronegative repulsion of fluoride.
Departmental Bulletin Paper