Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China.
Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China.
Bioelectrochemistry. 2018 Aug;122:40-50. doi: 10.1016/j.bioelechem.2018.03.003. Epub 2018 Mar 11.
The corrosion behavior of X65 steel was investigated in the seawater inoculated with sulfate reducing bacteria (SRB) under the aerobic environment by electrochemical impedance techniques and immersion tests. The corroded morphologies and the composition of the corrosion products were investigated. The variation of the solution parameters including the bacterium number, the pH value and the soluble iron concentration were also investigated. The results indicated that in the SRB-containing system, the impedance responses presented a depressed semi-circle in the initial period, which then turned into the blocked electrode characteristic during the later immersion. The biofilm, mainly composed of extracellular polymeric substances, Fe(OH), γ-FeOOH and α-FeO, formed and degraded with the SRB growth. The soluble iron concentration initially increased, then rapidly decreased and later slowly increased. In the SRB-containing seawater under the aerobic environment, the X65 steel was corroded in the initial immersion. The corrosion became inhibited with the forming of the biofilm during the subsequent immersion. The inhibition efficiency rapidly increased in the logarithmic phase, remained stable in the stationary phase and then decreased in the declination phase. In the corrosion process, the biofilm metabolized by SRB played a key role in the corrosion inhibition of X65 steel.
采用电化学阻抗技术和浸泡实验研究了有氧条件下接种硫酸盐还原菌（SRB）的海水中 X65 钢的腐蚀行为。研究了腐蚀形貌和腐蚀产物的组成，还研究了溶液参数（包括细菌数量、pH 值和可溶性铁浓度）的变化。结果表明，在含 SRB 的体系中，阻抗响应在初始阶段呈现出一个压低的半圆，随后在后期浸泡过程中转变为被阻塞的电极特性。生物膜主要由胞外聚合物、Fe(OH)、γ-FeOOH 和 α-FeO 组成，随着 SRB 的生长而形成和降解。可溶性铁浓度最初增加，然后迅速下降，随后缓慢增加。在有氧条件下含 SRB 的海水中，X65 钢在初始浸泡时被腐蚀。随后随着生物膜的形成，腐蚀受到抑制。在对数阶段，抑制效率迅速增加，在稳定阶段保持稳定，然后在下降阶段下降。在腐蚀过程中，SRB 代谢的生物膜在 X65 钢的腐蚀抑制中起着关键作用。
