Effect Of Bacteria Medium And Biofilm Formation On The Electrochemical Behaviour Of A Polished Austenitic Stainless Steel

This work aims to study the effect of biotic medium and the AISI316L stainless steel microstructure, and the electrochemical behaviour and the formation of bacteria microcolonies. The electrochemical study via potentiostatic tests, compared between two bacterial systems and a chemical aqueous solution of FeCl3. The results indicate a decrease of corrosion rate of the AISI 316L specimen when the interface specimen/bacteria medium is covered by a biofilm. The acidifying bacterial solutions (Pseudomonas aeruginosa, Streptococcus thermophilus) seems to be more aggressive then FeCl3 solution with same acidity (pH 5.6). The modification of electrochemical medium and the interface proprieties seems to be an interesting way to improve the biocorrosion of the austenitic stainless steel. The presence of a Ps.a biofilm layer on AISI316L specimen has an effect on relaying the electrochemical kinetic of corrosion. The resistance to pitting in the presence of the biofilm layer was evaluated by recording the potentiostatic curves upto 15 hours of immersion.