Accelerated Corrosion of 316L Stainless Steel Caused by Shewanella algae Biofilms

Abstract

In the marine environment, microbiologically influenced corrosion (MIC) is a major problematic issue, which leads to severe damage to metals and alloys. The prerequisite to mitigate this worldwide problem is to investigate the mechanisms of marine-corroding microbes. Therefore, the corrosion behavior of 316L stainless steel in the presence of marine Shewanella algae was investigated by means of electrochemical measurements and surface analysis. The results revealed that S. algae is capable of forming a dense and thick biofilm on the surfaces of 316L SS coupons after 7 days of incubation, which reached about a thickness of 40.4 μm. According to electrochemical results, the S. algae biofilm also induced the corrosion of 316L SS coupons. The accelerated corrosion of 316L SS coupons was in the form of pits, which was formed underneath the biofilms. The largest pit depth after 14 days of incubation time reached 9.8 μm, which was 6.7 times higher than the one immersed in abiotic medium (1.45 μm). This is the first study demonstrating the MIC of 316L SS due to the S. algae biofilm.

Development of Antibacterial V/TiO2-Based Galvanic Coatings for Combating Biocorrosion

“…The biofilm can produce extracellular polymeric substances (EPS), which contain proteins, polysaccharides, lipids, and nucleic acid, and it enhances the adhesion of bacteria within the biofilm . The EPS can increase the dissolution of the zinc coating, promoting the corrosion reaction on the metal surface. ,, Surface irregularities and defect of the pure zinc coating facilitates rapid attachment, colonization, and proliferation of bacteria . The bacteria are interconnected with each other, mainly in defects and cracks of the pure zinc coating.…”

“…53 The EPS can increase the dissolution of the zinc coating, promoting the corrosion reaction on the metal surface. 1,54,55 Surface irregularities and defect of the pure zinc coating facilitates rapid attachment, colonization, and proliferation of bacteria. 53 The bacteria are interconnected with each other, mainly in defects and cracks of the pure zinc coating.…”

Testing the Test: A Comparative Study of Marine Microbial Corrosion under Laboratory and Field Conditions

“…The activity of phototrophic bacteria and eukaryotes has a crucial role in corrosion processes. , The presence of macroalgae can create a local increment of dissolved oxygen due to photosynthesis, thereby promoting an increase in the cathodic current and, consequently, increasing the overall corrosion process. − The presence of photosynthetic organisms was observed clearly in the samples immersed at 5 m, where the complex biomass on the surface influences the observed differences in the current density (Figure B) and polarization resistance (Table ). Nonetheless, given the used experimental design, it was not possible to discriminate and quantify the contribution of microorganisms to these differences over those given by abiotic factors and the presence of macroalgae.…”

“…53 Most likely, macroorganisms (algae) had more influence due to the release of oxygen 22 and the development of a complex biofilm structure. 39 The development of this type of matrix on the exposed surfaces creates a reactive barrier due to the formation of several microgalvanic cells, which can generate fluctuations in the electrochemical responses related to the metal/film interphase. Then, corrosion processes can be promoted.…”

Microbiologically influenced corrosion of stainless steel independent of sulfate-reducing bacteria

“…Laboratory-scale corrosion experiments using electrochemically active microorganisms have been reported recently ( Miller et al, 2018 ; Dou et al, 2019 ; Kalnaowakul et al, 2020 ; Tang et al, 2021 ; Huang et al, 2022 ). Because various microorganisms live in complex community structure in the actual environments, understanding the mechanism of MIC by a single microorganism is inadequate.…”