Effects of cathodic polarization on X65 steel inhibition behavior and mechanism of mixed microorganisms induced corrosion in seawater

Abstract

The laws of cathodic polarization on bacterial growth, biofilm formation and effects on the corrosion process of X65 steel were investigated when sulfate-reducing bacteria (SRB) and iron-oxidizing bacteria (IOB) are mixed using surface analysis and electrochemical measurements. Results indicate that insufficient potentials could not inhibit the localized corrosion, but increased the metabolic activities of bacteria. Effective protection could be achieved when the potential was negatively shifted to − 1050 mV vs. SCE. The effects of cathodic polarization on the precess of biofilms formation were also investigated. The − 1050 mV vs. SCE polarization potential could inhibit the biological activity of sessile bacteria, destroy the biofilm structure and inhibit the corrosion process induced by each biofilm.