Bacillus widely exists in wet natural environment such as soil, water and air, and is often studied as one of representative microorganisms for microbiologically influenced corrosion(MIC) research. In this paper, the growth curve of Bacillus subtilis isolated from marine environment was determined by turbidimetry and its effect on corrosion behavior of 10MnNiCrCu steel was studied by open circuit potential, AC impedance, polarization curve and scanning electron microscopy(SEM). The results showed that with the change of the growth curve of Bacillus subtilis(BS), the open circuit potential(Eocp) shifted positively and then negatively, and the charge transfer resistance shown by AC impedance was much lower than that of the sterile system, increasing first and then decreasing. The polarization curves showed that the corrosion current density in BS medium was obviously higher than that in sterile system. The corrosion morphology observation showed that although a biofilm by BS developed on the steel surface, the localized corrosion of 10MnNiCrCu steel was aggravated due to the acidness of the metabolite itself and the biofilm with access for electrolyte ions.

中文翻译：

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枯草芽孢杆菌对海洋环境中10MnNiCrCu钢腐蚀行为的影响。

芽孢杆菌广泛存在于潮湿的自然环境中，例如土壤，水和空气中，并经常作为微生物学上受微生物影响的腐蚀（MIC）研究的代表微生物而被研究。通过比浊法测定了从海洋环境分离的枯草芽孢杆菌的生长曲线，并通过开路电势，交流阻抗，极化曲线和扫描电镜（SEM）研究了其对10MnNiCrCu钢腐蚀行为的影响。结果表明，随着枯草芽孢杆菌（BS）生长曲线的变化，开路电势（Eocp）先向后负移动，以交流阻抗表示的电荷转移电阻远低于无菌系统。先增加然后减少。极化曲线表明，BS介质中的腐蚀电流密度明显高于无菌系统。腐蚀形态观察表明，尽管通过BS形成的生物膜在钢表面形成，但10MnNiCrCu钢的局部腐蚀由于代谢物本身和接触电解质离子的生物膜的酸性而加剧。