METHOD FOR STUDYING STABILIZATION OF LOCALIZED CORROSION ON CARBON-STEEL BY SULFATE-REDUCING BACTERIA

Initiation of a corrosion pit in plain carbon steel (CS) was simulated by preconditioning a small area and a larger concentric area as an an ode and cathode, respectively. Preconditioning was achieved by applyin g a galvanic current between the electrodes, During this initial step, the effect of sulfate-reducing bacteria (SRB) on resulting polarizati on of this artificial galvanic cell was investigated. The previously c onditioned electrodes then were Left short-circuited, and the naturall y flowing galvanic current was measured using a zero-resistance ammete r. In the presence of SRB biofilms, an active and naturally stable gal vanic cell was achieved In sterile conditions, the coupling current ei ther was unstable or very low. This technique was aimed at studying ri sk factors linking bacterial contamination to the onset of rapid pitti ng corrosion.