Mechanism of Mn on inhibiting Fe-caused magnesium corrosion

Lei Yang; Shouzhen He; Chao Yang; Xiaorong Zhou; Xiaopeng Lu; Yuanding Huang; Gaowu Qin; Erlin Zhang

Journal of Magnesium and Alloys (Mar 2021)

Mechanism of Mn on inhibiting Fe-caused magnesium corrosion

Lei Yang,
Shouzhen He,
Chao Yang,
Xiaorong Zhou,
Xiaopeng Lu,
Yuanding Huang,
Gaowu Qin,
Erlin Zhang

Affiliations

Lei Yang: Key Laboratory for Anisotropy and Texture of Materials, Education Ministry of China, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China; State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China; Corresponding author at: Key Laboratory for Anisotropy and Texture of Materials, Education Ministry of China, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.
Shouzhen He: Key Laboratory for Anisotropy and Texture of Materials, Education Ministry of China, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China
Chao Yang: Key Laboratory for Anisotropy and Texture of Materials, Education Ministry of China, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China
Xiaorong Zhou: Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester M13 9PL, England, UK
Xiaopeng Lu: Shenyang National Laboratory for Materials Science, Northeastern University, 3-11 Wenhua Road, Shenyang 110819, China
Yuanding Huang: Institute of Materials Research, Helmholtz Zentrum Geesthacht, Max-Planck-Str. 1, D-21502 Geesthacht, Germany
Gaowu Qin: State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China
Erlin Zhang: Key Laboratory for Anisotropy and Texture of Materials, Education Ministry of China, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China; Corresponding author.

Journal volume & issue: Vol. 9, no. 2
pp. 676 – 685

Abstract

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In the present study, to understand the mechanism of Mn on inhibiting Fe-caused Mg corrosion, the corrosion behaviour of commercial pure Mg and Mg-6Mn alloy in 0.6 M NaCl solution is investigated. It is found that in Mg-6Mn alloy, Fe impurity is incorporated into Mn to form Mn (Fe) phase with Fe as solid solute. The initial galvanic corrosion cannot be reduced through converting Fe-rich phase to Mn (Fe) phase, since Mn (Fe) phase also has relatively strong cathodic activity and has much larger volume fraction than Fe-rich phase. However, the cathodic activation behaviour of pure Mg is inhibited. The cathodic activity even decreases for Mg-Mn alloy with increased exposure time, due to the reduced cathodic HER at the Mn (Fe) particles. Mn can be oxidized at the OCP of Mg-6Mn alloy, resulting in relatively dense Mn-rich corrosion film on particle surface, which separates the particle from the electrolyte and, consequently, inhibits HER.

Published in Journal of Magnesium and Alloys

ISSN: 2213-9567 (Online)
Publisher: KeAi Communications Co., Ltd.
Country of publisher: China
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.keaipublishing.com/en/journals/journal-of-magnesium-and-alloys/

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