氯离子对AZ91镁合金微生物腐蚀的影响

摘 要：本文研究了Cl-对AZ91镁合金微生物腐蚀的影响。硫酸盐还原菌(SRB)在镁合金表面形成生物膜，能够对Cl-穿透生物膜到达金属表面起到阻挡作用。随着Cl- 浓度的增加，镁合金在含菌培养基中的平均腐蚀速度逐渐增加，腐蚀电位逐渐降低。当含菌培养基中的Cl-浓度小于1.5g/l时，Cl-对镁合金微生物腐蚀的影响不大；当Cl-浓度大于1.5g/l时，微生物生物膜的存在显著地降低了镁合金对Cl-的腐蚀敏感性。

Influence of chlorine ion on microbiologically influenced corrosion of AZ91 magnesium alloy

Abstract：In this study, the influence of chorine ion on microbiologically influenced corrosion (MIC) of AZ91 magnesium alloy was investigated. Sulfate-reducing bacteria formed biofilm on the AZ91 magnesium alloy surface after 8 days immersion in the SRB medium. The biofilm can impede the pervasion of Cl- from the solution to the interface between the metal surface and the biofilm. With the increase of Cl- concentration, free corrosion potential of magnesium alloy decreases and corrosion rate increases in the SRB medium. When Cl- concentration is less than 1.5g/l, the effect of Cl- for the MIC of magnesium alloy is weak. When Cl- concentration is more than 1.5g/l, the biofilm decreases the corrosive sensitivity of magnesium alloy evidently in the SRB medium.