Energy and Resources Institute, College of Engineering, Information Technology and Environment, Charles Darwin University, Darwin, Northern Territory, Australia.
Research Institute for Energy and Livelihood, College of Engineering, Information Technology and Environment, Charles Darwin University, Darwin, Northern Territory, Australia.
PLoS One. 2021 May 12;16(5):e0251524. doi: 10.1371/journal.pone.0251524. eCollection 2021.
Corrosion under flow conditions is a major problem in the transportation industry. Various studies have shown the direct impact of different flow rates on bacteria biofilm formation, mass transfer and resulting different corrosion behaviour of materials in neutral environments. However, little is understood on corrosion under acidic flow conditions. This study investigated the impact of an acidic artificial seawater environment containing Desulfovibrio vulgaris on DSS 2205 microbial corrosion under different velocities (0.25 m.s-1 and 0.61 m.s-1). Experiments containing no bacteria were performed as controls. Bacterial attachment was observed by optical and scanning electron microscope (SEM). Materials corrosion was assessed using open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Pits formed after potentiodynamic test were observed under SEM. The largest area of bacterial attachment was found on coupons immersed at a velocity of 0.25 m.s-1; however, the corrosion rate was lower than at higher velocity. Shallow pits occurred in the metal coupons when bacteria were present, while deep pits occurred in the controls. The study indicates the positive impact of biofilm formation in corrosion prevention of materials under acidic condition. The nature of corrosion behaviour of duplex stainless is discussed.
在流动条件下的腐蚀是运输行业的一个主要问题。各种研究表明，不同的流速对细菌生物膜形成、传质以及中性环境中材料产生的不同腐蚀行为有直接影响。然而，对于酸性流动条件下的腐蚀知之甚少。本研究调查了含有脱硫弧菌的酸性人工海水环境对 DSS 2205 微生物在不同流速（0.25 m.s-1 和 0.61 m.s-1）下的微生物腐蚀的影响。没有细菌的实验作为对照进行。通过光学显微镜和扫描电子显微镜（SEM）观察细菌附着。使用开路电位（OCP）、电化学阻抗谱（EIS）和动电位极化评估材料腐蚀。在 SEM 下观察动电位测试后形成的凹坑。在流速为 0.25 m.s-1 时，浸入的试片上发现了最大面积的细菌附着；然而，腐蚀速率低于较高流速。当有细菌存在时，金属试片上会出现浅凹坑，而在对照中则会出现深凹坑。该研究表明，在酸性条件下，生物膜的形成对材料的腐蚀防护有积极影响。讨论了双相不锈钢腐蚀行为的性质。
