Effect of Flow on Microbiologically Influenced Corrosion: Insights from a Novel Platform

Marine biofouling begins with microbial biofilm formation on submerged surfaces and represents a major challenge for marine infrastructure. Microfouling can directly induce microbiologically influenced corrosion (MIC), contributing to material degradation and structural integrity loss. Here, we investigate the impact of high laminar flow on MIC of carbon steel influenced by the Desulfovibrio ferrophilus IS5. Experiments were conducted using a newly developed Environmental Simulation System (ESS), designed to enable electrochemical monitoring of corrosion processes under controlled anaerobic, high-flow conditions. Corrosion behavior was assessed using electrochemical techniques, while surface morphology and corrosion product composition were analyzed by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). Localized corrosion was further quantified using 3D surface profiling. The results demonstrate that flow intensity strongly influences both biotic and abiotic corrosion behavior. Under abiotic conditions, severe pitting corrosion occurred, with average maximum pitting rates of 0.95 mm yr⁻¹. In the presence of Desulfovibrio ferrophilus IS5, localized corrosion intensified substantially, with pitting rates reaching up to 3.82 mm yr⁻¹. Tafel polarization revealed a severe average uniform corrosion rate of 0.41 mm yr⁻¹ under biotic conditions, compared to only 0.01 mm yr⁻¹ in the abiotic system. These findings highlight the critical role of hydrodynamics in microfouling-driven MIC and demonstrate the utility of the ESS platform for studying biofouling impacts under marine-relevant flow conditions.