Abstract：
The biological sulfur cycle is closely related to iron corrosion in the natural environment. The effect of the sulfur-oxidising bacterium Ectothiorhodospira sp., named PHS-Q, on the metal corrosion behaviour rarely has been investigated. In this study, the corrosion mechanism of Q235 carbon steel in a PHS-Q-inoculated medium is discussed via the characterization of the morphology and the composition of the corrosion products, the measurement of local corrosion and the investigation of its electrochemical behaviour. The results suggested that, initially, PHS-Q assimilates sulfate to produce H2S directly or indirectly in the medium without sulfide. H2S reacts with Fe2+ to form an inert film on the coupon surface. Then, in localised areas, bacteria adhere to the reaction product and use the oxidation of FeS as a hydrogen donor. This process leads to a large cathode and a small anode, which incurs pitting corrosion. Consequently, the effect of PHS-Q on carbon steel corrosion behaviour is crucial in an anaerobic environment.
摘要：
生物硫循环与自然环境中的铁腐蚀密切相关。硫氧化细菌的作用。,名为PHS-Q,对金属腐蚀行为的研究很少。在这项研究中,通过表征腐蚀产物的形貌和成分，讨论了Q235碳钢在PHS-Q接种介质中的腐蚀机理，局部腐蚀的测量及其电化学行为的研究。结果表明,最初,PHS-Q在没有硫化物的介质中同化硫酸盐以直接或间接产生H2S。H2S与Fe2+反应以在试样表面上形成惰性膜。然后，在局部地区，细菌粘附在反应产物上，并使用FeS的氧化作为氢供体。这个过程导致一个大的阴极和一个小的阳极，导致点蚀。因此,在厌氧环境中，PHS-Q对碳钢腐蚀行为的影响至关重要。
