The ennoblement of stainless steel by manganic oxide biofouling
Loading...
Date
1996-08
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Twenty-three 316L stainless steel (SS) coupons were exposed in situ to fresh river-water for periods of up to 35 days. All samples developed steady-state corrosion potentials (Ecorr) near + 350 mV (SCE) and polarization measurements showed enhanced cathodic current density characteristic of passive metal ennoblement. Epifluorescence and scanning electron microscopy of the attached biofilm showed numerous 10–20μm diameter Mn-rich annular deposits, associated clusters of bacterial cells, and abundant sheathed bacteria. Dissolution of the Mn deposits using Na2SO3 shifted Ecorr to pre-exposure values. SS coated with MnO2paste displayed electrochemical behavior nearly identical to that of ennobled samples. A mechanism of ennoblement by MnO2 biofouling is proposed which explains a variety of findings on the electrochemical behavior of microbially colonized SS.
Description
Keywords
Citation
Dickinson,W.H., F. Caccavo, Jr., and Z. Lewandowksi, “The Ennoblement of Stainless Steel by Manganic Oxide Biofouling,” Corrosion Science, 38(8):1407-1422 (1996).