Abstract:

Sulfate-reducing bacterium （SRB） was used to restrain the corrosion of AZ91 magnesium alloy in the solution containing chlorine ions, and a pitting corrosion was observed in both the sterile and the SRB samples. The results show that, when Cl^-content is less than 1.5 g/L, the two samples are of almost equal corrosion rate and possess only tiny pits on their surfaces, meaning that SRB only has slight effect on the corrosion of magnesium alloy in the solution with low Cl^- content. However, when Cl^-content is more than 1.5 g/L, the pits on the sample surfaces extend, and both of the corrosion rates increase with Cl^-content, especially the sterile sample. In addition, with the increase in Cl^-content, the corrosion current of SRB sample increases, while the corrosion potential decreases, thus coming to the conclusion that the existence of SRB biofilm greatly weakens the corrosive sensitivity of magnesium alloy to Cl^-

Key words: magnesium alloy, chlorine ion, microbiologically-influenced corrosion, sulfate-reducing bacterium