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Passivation-Induced Cr and Mo Enrichments of 316L Stainless Steel Surfaces and Effects of Controlled Pre-Oxidation.

Passivation-Induced Cr and Mo Enrichments of 316L Stainless Steel Surfaces and Effects of Controlled Pre-Oxidation.

Authors :
Lynch, Benjamin
Zuocheng Wang
Li Ma
Paschalidou, Eirini-Maria
Wiame, Frédéric
Maurice, Vincent
Marcus, Philippe
Source :
Journal of The Electrochemical Society; Nov2020, Vol. 167 Issue 14, p575-585, 11p
Publication Year :
2020

Abstract

Passivation mechanisms and the effects of controlled pre-oxidation, by exposure to oxygen at ultra-low pressure, on Cr and Mo surface enrichments were investigated on polycrystalline AISI 316L stainless steel surfaces with direct transfer between surface preparation and analysis by X-ray photoelectron spectroscopy and electrochemistry. Exposure to sulfuric acid at open circuit potential causes preferential dissolution of oxidized iron species, which promotes Cr<superscript>3+</superscript> and Mo<superscript>4+/6+</superscript> enrichments. Anodic passivation forces oxide film re-growth and Cr<superscript>3+</superscript> dehydroxylation with no loss of Mo<superscript>4+/6+</superscript> pre-enrichment. Ultra-low pressure preoxidation promotes Mo<superscript>4+/6+</superscript> enrichment in the exchange outer hydroxide layer of the passive film, with no Mo0 depletion in the modified alloy region underneath the oxide film at open circuit potential, and under anodic passivation. Mo<superscript>4+/6+</superscript> enrichment improves protectiveness against transient active dissolution during the active/passive transition [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00134651
Volume :
167
Issue :
14
Database :
Supplemental Index
Journal :
Journal of The Electrochemical Society
Publication Type :
Academic Journal
Accession number :
147782445
Full Text :
https://doi.org/10.1149/1945-7111/abc727