J. Mater. Sci. Technol. ›› 2007, Vol. 23 ›› Issue (03): 323-328.

• Research Articles • Previous Articles     Next Articles

Effect of Sulfate-reducing Bacteria on Corrosion Behavior of Mild Steel in Sea Mud

Xiaodong ZHAO, Jizhou DUAN, Baorong HOU, Suru WU   

  1. Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
  • Received:2006-06-12 Revised:2006-07-31 Online:2007-05-28 Published:2009-10-10
  • Contact: Jizhou DUAN

Abstract:

Microbiologically influenced corrosion (MIC) is very severe corrosion for constructions buried under sea mud environment. Therefore it is of great importance to carry out the investigation of the corrosion behavior of marine steel in sea mud. In this paper, the effect of sulfate-reducing bacteria (SRB) on corrosion behavior of mild steel in sea mud was studied by weight loss, dual-compartment cell, electronic probe microanalysis (EPMA), transmission electron microscopy (TEM) combined with energy dispersive X-ray analysis (EDX) and electrochemical impedance spectroscopy (EIS). The results showed that corrosion rate and galvanic current were influenced by the metabolic activity of SRB. In the environment of sea mud containing SRB, the original corrosion products, ferric (oxyhydr) oxide, transformed to iron sulfide. With the excess of the dissolved H2S, the composition of the protective layer formed of FeS transformed to FeS2 or other non-stoichiometricpolysulphide, which changed the state of the former layer and accelerated the corrosion process.

Key words: Microbiologically influenced corrosion (MIC), Sulfate-reducing bacteria (SRB), Mild steel, Sea mud