Effect of Iron-Oxidizing Bacteria on Pitting of Stainless Steel

Abstract

Microbiologically influenced corrosion (MIC) of stainless steel (SS) can be caused by the action of metal-oxidizing bacteria (MOB) in natural, relatively low-chloride waters. This type of corrosion is frequently associated with ennoblement of the open-circuit potential and involves iron-oxidizing bacteria (IOB) and manganese-oxidizing bacteria (MnOB). This work focuses of the role of IOB and associated inorganic water chemistry processes that may cause corrosion of SS. Laboratory and field studies have been conducted to investigate the influence of deposited ferric oxide (or oxyhydroxide) on the corrosion of UNS S30403. Samples exposed to a natural spring water reached open-circuit potentials of 250 mV vs saturated calomel electrode (SCE) and were covered by a biofilm containing a mixture of geothite (α-FeOOH), lepidocrocite (γ-FeOOH), and magnetite (Fe 3 O 4 ) or maghemite (γ-Fe 2 O 3 ), together with low levels of manganese-based deposits. In the laboratory, an iron-based film was formed on some samples by oxidation of ferrous sulfate (FeSO4 ) with calcium hypochlorite (Ca[ClO] 2 ), giving a surface film with a composition similar to that produced by microbial activity. These samples did not show ennoblement, but they did show lower pitting potentials than were measured for control samples. The results of this work are consistent with the idea that MIC of SS in potable water involves manganesebased deposits causing ennoblement (W.H. Dickinson, F. Caccavo Jr.

Corrosion behavior of carbon steel in the presence of sulfate reducing bacteria and iron oxidizing bacteria cultured in oilfield produced water

“…MIC or biofouling is often caused by a mixture of microorganisms, including anaerobic and aerobic bacteria [4,5]. For example, anaerobic sulfate-reducing bacteria (SRB) and aerobic iron-oxidizing bacteria (IOB) are sometimes found together in the biofilm in the field [6,7]. In an anaerobic environment, SRB used sulphate as electron acceptor and FeS and Fe(OH) 2 are often the main corrosion products [8][9][10].…”

Chemical composition and electronic structure of the passive layer formed on stainless steels in a glucose-oxidase solution

“…In natural aerated waters, an increase of the free corrosion potential E corr (or open circuit potential OCP) of stainless steel (SS) samples is frequently observed as a consequence of the settlement of a biofilm on the metallic surface [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The OCP rises quickly until it reaches values ranging between +100 and +350 mV/SCE, which enhances the risk of initiation of pitting corrosion and therefore is a threat to the metal durability.…”

Microbially influenced corrosion of steels by Pseudomonas aeruginosa

“…The metal-oxidizing bacteria generally lead to the production of aggressive compounds that induce corrosion damage (Chamritski, Burns, Webster, & Laycock, 2004). The SFBs can also induce corrosion through the formation of differential aeration cells (Hamzah et al, 2013).…”