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

doi:10.1016/j.jma.2020.09.015

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

Materials Engineering

Research output: Contribution to journal › Article › peer-review

Abstract

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.

Original language	English
Journal	Journal of Magnesium and Alloys
Early online date	16 Nov 2020
DOIs	https://doi.org/10.1016/j.jma.2020.09.015
Publication status	E-pub ahead of print - 16 Nov 2020

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https://linkinghub.elsevier.com/retrieve/pii/S2213956720302061

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@article{3363b79538b44911969cfe63207e858c,

title = "Mechanism of Mn on inhibiting Fe-caused magnesium corrosion",

abstract = "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.",

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

year = "2020",

month = nov,

day = "16",

doi = "10.1016/j.jma.2020.09.015",

language = "English",

journal = "Journal of Magnesium and Alloys",

issn = "2213-9567",

publisher = "Chongqing University, National Engineering Research Center for Magnesium Alloys of China",

}

TY - JOUR

T1 - Mechanism of Mn on inhibiting Fe-caused magnesium corrosion

AU - Yang, Lei

AU - He, Shouzhen

AU - Yang, Chao

AU - Zhou, Xiaorong

AU - Lu, Xiaopeng

AU - Huang, Yuanding

AU - Qin, Gaowu

AU - Zhang, Erlin

PY - 2020/11/16

Y1 - 2020/11/16

N2 - 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.

AB - 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.

U2 - 10.1016/j.jma.2020.09.015

DO - 10.1016/j.jma.2020.09.015

M3 - Article

SN - 2213-9567

JO - Journal of Magnesium and Alloys

JF - Journal of Magnesium and Alloys

ER -

Mechanism of Mn on inhibiting Fe-caused magnesium corrosion

Abstract

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