海水中硫酸盐还原菌作用下Q235钢表面腐蚀产物的形成和转化

用扫描电镜、电子探针、透射电镜及能谱仪等分析手段，研究了Q235钢在含有硫酸盐还原菌的海水中表面腐蚀产物的形成和转化。研究表明，硫酸盐还原菌首先在钢表面附着，随着细菌生命代谢活动的进行，最初的腐蚀产物由球形的（水合）氧化铁转化为海绵状的球形铁硫化物。腐蚀产物中存在FeS单晶。

Study of influence by sulfate-reducing bacteria on formation of corrosion products on the surface of Q235 steel

The formation of corrosion products on the surface of Q235 steel in seawater containing sulfate-reducing bacteria(SRB) was studied by scanning electronic microscopy(SEM), electronic probe microanalyzer(EPMA) and transmission electron microscopy(TEM) combined with energy dispersive X-ray detector(EDX) in this paper. SEM observation showed that the corrosion commenced with the attachment of bacteria to the steel surface, producing organic acids, hydrogen sulphide and extracellular polymer substances(EPS). Globules of hydrated ferric oxide were the primary form of corrosion products. With exposure to further deterioration caused by SRB, their transformation to spongy globules of iron sulphide was observed by EPMA. The presence of single crystal FeS in the corrosion products was identified by electronic diffraction pattern of TEM and composition analysis by EDX.