Corrosion of an AZ31B Magnesium Alloy by Sulfate-Reducing Prokaryotes in a Mudflat Environment

Xiao Lan; Jie Zhang; Zaifeng Wang; Ruiyong Zhang; Wolfgang Sand; Liang Zhang; Jizhou Duan; Qingjun Zhu; Baorong Hou

doi:10.3390/microorganisms10050839

Corrosion of an AZ31B Magnesium Alloy by Sulfate-Reducing Prokaryotes in a Mudflat Environment

Microorganisms. 2022 Apr 19;10(5):839. doi: 10.3390/microorganisms10050839.

Authors

Xiao Lan^{1

2

3}, Jie Zhang^{1

2

3}, Zaifeng Wang⁴, Ruiyong Zhang^{1

2

3}, Wolfgang Sand^{5

6

7}, Liang Zhang⁴, Jizhou Duan^{1

2

3}, Qingjun Zhu^{1

2

3}, Baorong Hou^{1

2

3}

Affiliations

¹ CAS Key Laboratory of Marine Environmental Corrosion and Bio-Fouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
² Open Studio for Marine Corrosion and Protection, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China.
³ University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Centre of Ocean Information Science and Technology, China National Offshore Oil Information Technology Co., Ltd., Beijing 100029, China.
⁵ Aquatic Biotechnology, University of Duisburg-Essen, 45141 Essen, Germany.
⁶ Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
⁷ Institute of Biosciences, Freiberg University of Mining and Technology, 09599 Freiberg, Germany.

Abstract

To study the abnormal failure of magnesium anodes for buried pipelines in marine engineering in the unique environment of mudflats, a strain of a sulfate-reducing prokaryote (SRP) was isolated from pipe-laying soil, and identified as Desulfovibrio sp. HQM3. Weight-loss test, electrochemical measurements, SEM, EDS, XRD, and CLSM techniques were used to study the effect of corrosion on the AZ31B magnesium alloy. Under the influence of SRP, the magnesium alloy corroded severely at rates up to 1.31 mm/year in the mudflat environment. SRP accelerated corrosion by 0.3mm/year. Pitting occurred on the samples in both abiotic and biotic systems. The pitting depth reached 163.47 μm in the biotic system after 14 days. The main composition of a petal-like corrosion product was Mg(OH)₂. The results show that a mudflat environment can lead to an accelerated corrosion of magnesium alloys.

Keywords: Microbiologically Influenced Corrosion; electrochemical impedance spectroscopy; magnesium alloy; mudflat environment; sulfate–reducing prokaryotes.

Abstract

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