Evaluation of microbiologically influenced corrosion of Ti6-Al4-V (TC4) alloy in the marine oil industry
作者
单位
1Key Laboratory of Material Chemistry for Energy Conversion and Storage、Ministry of Education、Hubei Key Laboratory of Material Chemistry and Service Failure、Hubei Engineering Research Center for Biomaterials and Medical Protective Materials、School of Chemistry and Chemical Engineering、Huazhong University of Science and Technology、Wuhan 430074、P. R. China
关键词
收录来源
International Corrosion Congress · 第22届国际腐蚀大会
摘要
Titanium alloy, as an excellent lightweight alloy, has a promising application in the marine oil industry. However, they are not immune to SRB erosion. SRB biofilm can colonize the surface of TC4 alloy well and trigger severe MIC and localized corrosion. The addition of riboflavin significa ntly unaffected the SRB planktonic and sessile cell counts, but enhanced the biofilm thickness slightly. Hilbert -Huang transform showed that corrosion pits on the surface of TC4 alloy was triggered by SRB biofilm and enhanced by riboflavin. The maximum corrosion pit depths in biotic medium with 0 ppm, 20 ppm, and 50 ppm riboflavin reach 5.71 μm, 6.38 μm, and 6.65 μm, respectively. The lower Rct values were associated with riboflavin, which shuttled electrons from the metal surface to SRB cells. Mott -Schottky curves showed the property of n -type semiconductor oxide films on the surface of TC4. The higher ND values in biotic medium with electron shuttle demonstrated that SRB cells promoted by riboflavin-shuttle contributed to more passivation film defects on the surface of TC4 alloy and weakened the oxide film. MIC could influence the alloy phase composition, grain size and organization.