Study on Corrosion Behavior of X80 Steel under Stripping Coating by Sulfate Reducing Bacteria

Abstract

Background: At present, microorganism has been considered as important factors that threaten to buried pipelines with disbonded coatings. Aiming at the problem of unknown corrosion mechanism of sulfate-reducing bacteria (SRB), a series of studies have been carried out in this paper. Spectrophotometer and fluorescent labeling technology are used to study the growth and attachment of SRB in the simulated soil solution. The electrochemical behavior of X80 pipeline steel with or without SRB was researched by electrochemical methods such as open circuit potential, dynamic potential polarization curve, and electrochemical impedance spectroscopy. The microscopic morphology of the corrosion products on the surface of the sample was observed with a scanning electron microscope (SEM), and the element content of the corrosion products on the surface of the sample after corrosion was observed using X-ray energy spectrum (EDS) analysis. Results: The results showed that the growth and reproduction of SRB caused the pH of the soil simulated solution to increase, which promoted the corrosion of X80 steel. In addition, the cathode reaction of X80 steel in a sterile environment is the reduction of H+, and the main corrosion product is Fe oxides. When the soil simulation solution contains SRB, the cathodic reaction is controlled by both H+ reduction and sulfide depolarization reactions, and FeS appears in the corrosion products. Conclusion: Although the life cycle of SRB is only about 14 days, the corrosion of X80 steel is greatly promoted by SRB, and even causes corrosion perforation, which will bring huge economic losses and serious safety hazards.

Effects of stress, strain rate and sulfate-reducing bacteria on corrosion behavior of X70 pipeline steel

“…Tokuda et al (2021) discovered that stress improved the anodic dissolution of the steel (Zhang et al, 2009). Chen et al (2021aChen et al ( , 2021bChen et al ( , 2021c; Cui et al (2021aCui et al ( , 2020Cui et al ( , 2021b discovered that the metal corrosion rates in SRB-containing solutions were higher than that in the sterile solutions. According to Chen and Zhang (2018), Lv et al (2020), SRB interfered with the electrochemical reactions that happened during polarization, increasing the cathodic current.…”

Nanocomposites based on biocompatible polymers and graphene oxide for antibacterial coatings

“…The colonization of bacteria on surfaces can give an adverse impact on the function of instruments such as petroleum pipelines, aquatic systems, textiles, food packages, contact lenses, and medical devices. 1–3 These negative impacts include the worsening of surface functions and properties 4 ; surface corrosion 5 ; bacterial contaminations 6,7 ; biofouling 8 ; chronic infection 7 ; and even deaths. 9 Food packaging without antibacterial coatings may cause quality deterioration and spoilage of foods.…”