含有硫酸盐还原菌的海泥中阴极保护电位对碳钢腐蚀的影响

Influence of Cathodic Protection Potential on Corrosion of Carbon Steel in Seamud Containing SRB

对含有SRB海泥中的碳钢的阴极保护的可靠性进行了评价,重点研究了不同保护电位下碳钢的交流阻抗行为,并结合失重法、MPN法细菌计数,得出极化电位、腐蚀速度以及细菌活性之间的关系。3种极化电位下碳钢的腐蚀速度与交流阻抗谱表明,在本试验条件下,碳钢在-950 mV极化电位下受到了较好的保护,腐蚀速度稳定且相对较小。细菌计数表明在较高阴极极化电位下细菌的生长活性与稳定性低于在低电位下的。分析表明,合适的保护电位应该比-950 mV更负。

The reliability of cathodic protection（CP） on carbon steel buried in sea mud containing SRB was evaluated with emphasis on electrochemical impedance spectra（EIS） under different CP potentials. The relationship among CP potential, corrosion rate and bacteria activities was summarized based on EIS results, weight-loss test and number-calculation of bacteria with MPN method, which showed that the steel under potential of -950 mV （CSE） was relatively well protected with a stable and low corrosion rate. The growth activities and stability of SRB were low under higher CP potential. - 950 mV or even lower potential was needed to ensure effective protection.