Synergistic effects of deposits and sulfate reducing bacteria on the corrosion of carbon steel

The synergistic effects of deposits and sulfate reducing bacteria (SRB) on the corrosion of a carbon steel are clarified by purposely designing four groups of experiments. The weight loss combined with electrochemical measurements and the surface profiling determine quantitatively that deposits and SRB contribute synergistically ~75% and ~ 49% to uniform and localized corrosion, respectively. Based on the experimental evidence, the synergism is explained in terms of the promotion effects of SRB on under-deposit corrosion (UDC) due to unevenly distributed iron sulfides produced by SRB and the acceleration effects of deposits on SRB corrosion resulting from UDC-induced accumulation of SRB.