Microbiologically influenced corrosion of FeCoCrNiMo0.1 high-entropy alloys by marine Pseudomonas aeruginosa

Abstract

The microbiologically influenced corrosion of a FeCoCrNiMo0.1 high-entropy alloy (HEA) by Pseudomonas aeruginosa was investigated. Compared to uncorroded samples in sterile medium, pitting corrosion was found on HEA surfaces after 14 day-immersion in inoculated medium. Electrochemical tests, X-ray photoelectron spectroscopy and Auger electron spectroscopy demonstrated that the passive film was weaken and thinned by the P. aeruginosa biofilm. In the presence of biofilms, selective dissolution occurred on the HEA, particularly when the organic nutrient was insufficient. When the organic nutrient was reduced from 100% to 10% in the medium, the amount of dissolved iron increased from 188.4 to 712.9 μg/L.