Scanning electrochemical microscopy measurement of ferrous ion fluxes during localized corrosion of steel

Local fluxes of ferrous ions at low carbon steel surfaces coated with tin and an epoxy-phenolic resin on tinplate samples, and at chrome steel (tin-free steel) have been monitored by oxidation of Fe2+ ions at the tip of a Pt scanning electrochemical microscope (SECM). The samples were immersed in 10 mM H2SO4 in order to avoid Fe(OH)(3) precipitation. The SECM was employed in the collection mode at constant height (approximate to 10-15 mu m) on an x-y plane above the sample, monitoring the tip current as a function of tip location. (c) 2005 Elsevier B.V. All rights reserved.