Study on microbiologically influenced corrosion of HSLA-65 steel

Abstract

In the current study, the corrosion behavior of HSLA-65 steel was investigated in a simulated marine environment inoculated with P. aeruginosa. In the electrochemical measurements, the negative shift in OCP, lower values of corrosion potential, pitting potential, and increased corrosion current density of the HSLA-65 steel in the biotic medium signified its low corrosion resistance in the presence of P. aeruginosa. The observation of the surface morphology revealed biofilm formation on the steel surface in the P. aeruginosa-inoculated culture medium, which significantly accelerated the pitting corrosion of the steel. The pit observed on the steel surface in the biotic medium was about 3.9 times deeper than in the sterile medium. In addition, the weight loss of the steel in the biotic medium was about 2.4 times higher compared to that in the sterile medium. These findings suggest that the P. aeruginosa biofilm significantly accelerated the corrosion of HSLA-65 steel in the simulated marine environment.

Keywords

• HSLA-65 steel
• Pseudomonas aeruginosa
• Marine environment
• Microbiologically influenced corrosion