Microbiological influence on the electro‐chemical potential of stainless steel

Abstract

The microbiologically caused ennoblement appears in natural water on all stainless steels equally and can only be prevented by the use of biocides. Temperature and supply of nutrients have an influence on the increasing rate of the potential, as well as the presence of manganese ions in the water favors the potential rise. The final value of the potential is substantially regulated by the biological system and is independent of the steel composition.An endangerment of stainless steels by a selective corrosion attack e.g. pitting corrosion arises if the critical repassivation potential of the steel lies below the open-circuit potential appearing in the natural system. This can be due to the alloy composition or due to process-conditioned weakening of the passive layer, for example by annealing colors on and beside welded joints.

Electroactive Bacteria Associated With Stainless Steel Ennoblement in Seawater

“…As the OCP value gets closer to the pitting corrosion potential, the probability of stainless steel pitting and crevice corrosion initiation increases, hence the central problem raised by ennoblement (Mollica, 1992; Zhang and Dexter, 1995). Ennoblement is a biotic process as it is dependent on microbial colonization and development on the stainless steel surface (Motoda et al, 1990; Scotto and Lai, 1998; Le Bozec et al, 2001; Wei et al, 2005; Gümpel et al, 2006).…”

A graphenic and potentiometric sensor for monitoring the growth of bacterial biofilms

“…This study showed a negative correlation between bacterial growth on the working electrode surface and OCP, with a significant reduction of this latter during the exponential phase. Previous studies demonstrated that the direction of the potential change depends on the microorganism, the material where the biofilm develops and the environment [42,56]. Here, the OCP shift towards more negative values as the bacterial concentration increases may be explained by the interaction of a variety of factors.…”

“…Here, the open circuit potential (OCP) between a working and a reference electrode is measured to assess the analyte concentration/activity. The OCP transduction has long been used in the study of electrochemically active biofilms in marine ecosystems, where a change in the OCP may be associated to the biofilm biomass [42,43]. Potentiometric needle microsensors are also used to study biofilms without perturbing the system.…”

Review on the microbiologically influenced corrosion and the function of biofilms

“…These are based on longand short-range forces between bacteria and the surface, by surface energy approach; the physical and chemical interactions between the solid surface and the biofilm should also take into consideration. Other parameters that may influence the rating process of bacterial accumulation on metals are the surface hydrophobicity or hydrophilicity as well as the surface roughness [35][36][37][38][39][40][41][42]. Surface wettability that influences fouler colonization ranges from superhydrophobic to superhydrophilic surfaces [43][44][45].…”