天然海水中微生物膜对碳钢腐蚀行为的影响

Effect of biofilms on corrosion of carbon steel in seawater

通过对比碳钢在天然海水和灭菌海水中的腐蚀行为,研究海洋微生物对碳钢材料的腐蚀行为的影响。结果表明,海洋微生物可在碳钢表面形成微生物膜,其对碳钢腐蚀速率的影响及作用机理与微生物的种类密切相关。在腐蚀初期,海洋微生物膜对碳钢的腐蚀起到了抑制作用,主要由多种好氧微生物协同作用的结果;在腐蚀后期,随着海洋微生物膜增厚导致厌氧腐蚀的出现从而加速腐蚀,主要是硫酸盐还原菌等厌氧微生物的作用。

Steel infrastructure immersed in natural seawater is exposed to important corrosion phenomena. Marine microorganisms have a significant influence on marine steel corrosion. In this work, the effect of biofilms on the corrosion behaviors of Q235 steel was studied by comparing the corrosion behaviors of the carbon steel immersed in natural and sterile seawater. The corrosion behaviors were observed by using gravimetric, microbiological, elec- trochemical measurements and corrosion product analyses. In the early phase, biofilms can decrease the corrosion rate. This is because the rate oxygen diffusion from the medium onto the steel surface was limited by the formation and growth of biofilms. It is correlated with synergistic action of a variety of aerobic microorganisms. In the later phase, it is marked by an increased rate of corrosion. It is related to the rapid growth of anaerobic microorganisms, such as sulphate reducing bacteria.