Electropolishing of Type 304 Stainless Steel in an Amide-Type Ionic Liquid Containing Chloride Ion

The anodic dissolution of type 304 stainless steel (SUS304) and chromium were investigated in an amide-type ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) in the presence of Cl – . The constituents of SUS304 (Fe, Ni, and Cr) were dissolved through both the direct anodic dissolution and the simultaneous chemical etching by trichloride ion, Cl 3 – , to form their chlorocomplexes. Micro- and macro-smoothing of SUS304 were found to be possible after potentiostatic anodic electrolysis in 0.5 M BMPCl/BMPTFSA at 1.0 V vs Ag|Ag(I) and 343 K with agitation. The in-situ analysis of the local physical properties of the electrolyte using an impedance type electrochemical quartz crystal microbalance revealed that a viscous layer did not form near the electrode during the anodic dissolution of SUS304.