SRB对AZgl镁合金在两种培养基中腐蚀行为的影响

摘要

Soaking method, SEM and EDS analyses were applied to evaluate the influence and mechanism of sulfate-reducing bacteria (SRB) for the corrosion of AZ91 magnesium alloy in two kinds of culture media. The results show that, SRB can adhere and grow on the surface of AZ91, and then form a biofilm. The biofilm inhibits the corrosion of AZ91 at (30±1)℃. The biofilm formed in the culture medium with (NH4)2Fe(SO4) · 6H2O and C6H8O6 is loose, and plays a weak protective role for the matrix. Furthermore, Fe2+ ions in (NH4)2Fe(SO4) · 6H2O improve the metabolism of SRB significantly, however, they can form the deposition of FeS, which accelerates the corrosion of AZ91.%采用浸泡法、扫描电镜(SEM)和X射线能谱仪(EDS)研究了硫酸盐还原菌(SRB)在两种培养基中,对AZ91镁合金腐蚀行为的影响及其腐蚀机理.结果表明:在培养温度为(30±1)℃的条件下,SRB可以在AZ91表面附着、生长并形成生物膜,生物膜的存在抑制了AZ91的腐蚀.AZ91在含硫酸亚铁铵和维生素C的培养基中所形成的生物膜,其结构疏松,对基体的保护作用较弱.同时硫酸亚铁铵中的Fe2+明显促进了SRB的新陈代谢,但是会在镁会金表面形成FeS 沉淀,显著加速AZ91的腐蚀.