The study of microbiologically influenced corrosion of 2205 duplex stainless steel based on high-resolution characterization

•The microbiologically influenced corrosion (MIC) of 2205 duplex stainless steel (DSS) caused by sulfate-reducing bacteria (SRB) was studied via high-resolution characterization.•SRB caused severe localized corrosion of 2205 DSS.•The breakage of passive film caused by the vulcanization of Fe3O4 and dissolve of Cr2O3 accelerated corrosion process.•Extracellular electron transfer (EET), breakage of the passive film and inhibition of passive film repair contributed to SRB-induced corrosion in this study. Sulfate-reducing bacteria (SRB)-induced corrosion of 2205 duplex stainless steel (DSS) was investigated via novel high-resolution characterization. After 28 days of immersion, the corrosion rate of coupons in the SRB-inoculated medium was 10 times higher than that of coupons in the sterile medium. Corrosion products were absent from the top-part of the biofilm where acidic −COOH was present, which indicated corrosion was not caused by metabolites. SRB clung to the matrix and mutually dissolved, which may favor electron transmission. Extracellular electron transfer (EET), breakage of the passive film and inhibition of passive film repair contributed to SRB-induced corrosion in this study.