Influence of sulfate reducing bacterial biofilm on corrosion behavior of low-alloy, high-strength steel (API-5L X80)

By Faisal M. AlAbbasa,Charles Williamsonb, Shaily M. Bholaa, John R. Spearb, David L. Olsonc, Brajendra Mishrac, Anthony E. Kakpovbiaa
Published in Journal of Power Sources NULL 2014

Abstract

The utilization of high strength carbon steels in oil and gas transportation systems has recently increased. This work investigates microbiologically influenced corrosion (MIC) of API 5L X80 linepipe steel by sulfate reducing bacteria (SRB). The biofilm and pit morphology that developed with time were characterized with field emission scanning electron microscopy (FESEM). In addition, electrochemical impedance spectroscopy (EIS), polarization resistance (Rp) and open circuit potential (OCP) were used to analyze the corrosion behavior. Through circuit modeling, EIS results were used to interpret the physicoelectric interactions between the electrode, biofilm and solution interfaces. The results confirmed that the extensive localized corrosion activity of SRB is due to a formed biofilm and a porous iron sulfide layer on the metal surface. Energy Dispersive Spectroscopy (EDS) revealed the presence of different sulfide and oxide constituents in the corrosion products for the system exposed to SRB.

Read Article » Back