Stress-assisted microbiologically influenced corrosion mechanism of 2205 duplex stainless steel caused by sulfate-reducing bacteria

[Display omitted] •A comprehensive mechanism for microbiologically influenced corrosion is proposed.•The mechanism relies on preferential distribution habit of sulfate reducing bacteria.•Stress assists the process by means of galvanic effect and passive film degradation.•The multi-electron donors in stainless steel promote extracellular electron transfer. In the present work, we studied the stress-assisted microbiologically influenced corrosion mechanism of 2205 duplex steel caused by sulfate-reducing bacteria (SRB) in simulated seawater environment. The results suggested that SRB have a significant influence on the pitting behavior of 2205 DSS, and stress promotes the MIC behavior. The mechanism proposes that the ferrite phases and high-residual stress regions manifest as the preferential anodic electron donor for SRB respiration due to the galvanic effect caused by the composing duplex phases, high-stress regions and low-stress regions; this outcome leads to the preferential dissolution of ferrite phases and high-stress regions.