from the conferences organized by TANGER Ltd.
Microbial activity can represent a significant factor in the degradation of metallic materials. Nevertheless, microbially influenced corrosion (MIC) of magnesium alloys has received limited attention. Methanogens are microorganisms that use hydrogen to produce methane and can influence corrosion processes. The study of MIC requires experiments conducted in cultivation media; for methanogens, NITE 927 medium is commonly used, containing a wide range of chemical components. To correctly interpret the specific effect of methanogens on corrosion, it is essential to first assess the influence of key medium constituents on the corrosion behavior of the investigated material. This work focuses on the effect of HEPES and cysteine on the corrosion behavior of AZ31 alloy. Immersion tests and potentiodynamic polarization showed that HEPES significantly accelerates the corrosion of the AZ31 alloy and promotes the initiation of pitting corrosion. Cysteine also increases the corrosion rate of AZ31, although to a lesser extent. Neither HEPES nor cysteine adsorb on the corrosion products, which consist predominantly of magnesium hydroxide and magnesium phosphate.
Keywords: Microbially influenced corrosion; magnesium alloys; methanogens; HEPES; cysteine; NITE 927 culture medium© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.