Li Zhong, Yang Jike, Guo Huihua, Kumseranee Sith, Punpruk Suchada, Mohamed Magdy E, Saleh Mazen A, Gu Tingyue
Department of Chemical and Biomolecular Engineering, Institute for Corrosion and Multiphase Technology, Ohio University, Athens, OH, United States.
Corrosion and Protection Center, University of Science and Technology Beijing, Beijing, China.
Front Bioeng Biotechnol. 2022 Nov 7;10:1028462. doi: 10.3389/fbioe.2022.1028462. eCollection 2022.
Apart from pinhole leaks, MIC (microbiologically influenced corrosion) can also cause catastrophic failures such as pipe ruptures and support beam collapses due to mechanical property degradation or stress corrosion cracking. In this work, X80 pipeline steel dogbone coupons and square coupons were immersed in 150 ml broths containing , a common corrosive sulfate reducing bacterium (SRB), for up to 14 days. The headspace volumes in the anaerobic bottles were increased from 150 ml to 200 ml and 300 ml to increase MIC severity. After 14 days of SRB incubation in ATCC 1249 culture medium with X80 coupons at 37°C, the sessile cell counts were 6.5 × 10 cells cm for 150 ml, 2.3 × 10 cells cm for 200 ml and 1.4 × 10 cells cm for 300 ml headspace volumes, respectively owing to reduced HS cytotoxicity in the broth with a larger headspace because it allowed more biogenic HS to escape from the broth. Weight losses were 1.7 mg cm, 1.9 mg cm and 2.3 mg cm for 150 ml, 200 ml and 300 ml headspace volumes, respectively. The corresponding pit depths were 2.6 μm, 4.2 μm and 6.2 μm for 150 ml, 200 ml and 300 ml headspace volumes, respectively. Electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and potentiodynamic polarization results corroborated the increasing weight loss and pitting data trends as a result of increased headspace. Tensile testing of dogbone coupons after the 14-day SRB immersion test indicated that more severe MIC pitting led to a higher ultimate strain loss by up to 23% (300 ml headspace) compared to the abiotic control, while the ultimate strength losses for all headspace volumes were quite small (3% and lower).
除针孔泄漏外，微生物影响的腐蚀（MIC）还可能导致灾难性故障，如由于机械性能下降或应力腐蚀开裂导致的管道破裂和支撑梁坍塌。在这项工作中，将X80管道钢狗骨试样和方形试样浸入含有常见腐蚀性硫酸盐还原菌（SRB）的150毫升肉汤中长达14天。将厌氧瓶中的顶空体积从150毫升增加到200毫升和300毫升以增加MIC的严重程度。在37°C下，将X80试样在ATCC 1249培养基中进行14天的SRB培养后，对于150毫升、200毫升和300毫升顶空体积，固着细胞计数分别为6.5×10个细胞/平方厘米、2.3×10个细胞/平方厘米和1.4×10个细胞/平方厘米，这是由于顶空较大的肉汤中HS细胞毒性降低，因为它允许更多的生物源HS从肉汤中逸出。对于150毫升、200毫升和300毫升顶空体积，重量损失分别为1.7毫克/平方厘米、1.9毫克/平方厘米和2.3毫克/平方厘米。相应的点蚀深度对于150毫升、200毫升和300毫升顶空体积分别为2.6微米、4.2微米和6.2微米。电化学阻抗谱（EIS）、线性极化电阻（LPR）和动电位极化结果证实了由于顶空增加导致重量损失和点蚀数据趋势增加。在14天的SRB浸泡试验后对狗骨试样进行拉伸试验表明，与非生物对照相比，更严重的MIC点蚀导致高达23%（300毫升顶空）的更高极限应变损失，而所有顶空体积的极限强度损失都相当小（3%及更低）。
