用交流阻抗技术、场发射扫描电镜和电子能谱等手段研究了在富集硫酸盐还原细菌海水作用下的Q235钢的腐蚀行为和锈层转化,比较了铁氧化物锈层对厌氧微生物腐蚀的影响.结果表明:表面已经存在铁氧化物锈层的碳钢,接种SRB菌液后,由于细菌的代谢产物(主要是硫化氢)与致密的铁氧化物发生反应,生成疏松的铁硫化物,最初使碳钢的腐蚀加速,随着细菌的生长,细菌代谢产生的胞外聚合物渗透到内层腐蚀产物上并粘连在一起,形成致密的保护层,腐蚀得到抑制.
It has been found that sulfate - reducing bacteria (SRB) play a significant role in microbiologicaUy anaembia corrosion process of steels exposed in aquatic enviromnents. In the practical enviromnent,an iron oxide rust could form initially firstly on the surface of the steel during aerobian corrosion,which was ignored by former researchers. The behavior of rusted steel as work electrode was studied in SRB -containing seawater by electrochemical impedance spectroscopy (EIS) and field emission scanning electron microscope (FE-SEM) and energy dispersive spectrometer (EDS). The biofilm was observed on the rust, the transformation of rust structure and components was also found. The results also showed that the corrosion rate of steel with iron oxide rust in seawaters inoculated SRB was accelerated in the initial stage,then with the bacteria proliferation,corrosion rate decreased and corrosion was inhibited. Considering the influence of biogenic hydrogen sulfide and extracellular polymeric substances, mixed bacteria community included iron-reducing bacteria, iron sulfide and possible electron transfer, the corrosion process of rusted carbon steel was discussed.