Ennoblement of stainless steel studied by x-ray photoelectron spectroscopy

Conference · Thu Dec 31 04:00:00 EST 1998

OSTI ID:350178

Olesen, B H ^[1]; Avci, R; Lewandowski, Z ^[2]

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1. Montana State Univ., Bozeman, MT (United States). Center for Biofilm Engineering
2. Montana State Univ., Bozeman, MT (United States)

Manganese oxides deposited by biofilms of Leptothrix discophora SP-6 on 316L stainless steel corrosion coupons increased the open circuit potential of the steel to values of +375 mV{sub SCE}. XPS spectra of the deposits compared to spectra of different manganese containing minerals indicated that the deposits were composed of MnO{sub 2}. The redox reaction responsible for the potential change results in electron transfer from the metal substratum to the mineral deposit. To study the processes of manganese dioxide reduction, MnO{sub 2} which had been electroplated on stainless steel was reduced electrochemically. The surface chemistry before and after reduction was analyzed by XPS. The authors demonstrated that the manganese dioxide deposited on stainless steel coupons can be reduced to Mn{sup 2+} by accepting two electrons from the metal. MnOOH was identified as an unstable intermediate product in this reaction. Consequently they hypothesize, that manganese dioxide microbially deposited on stainless steel surfaces can provide an efficient cathodic reaction and accelerate microbially influenced corrosion processes.

• OSTI ID: 350178
• Report Number(s): CONF-980316--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BIOLOGICAL FOULING
ELECTROCHEMICAL CORROSION
MANGANESE OXIDES
MINERALIZATION
REDOX REACTIONS
STAINLESS STEEL-316L