Accelerated sulfate reducing bacteria corrosion of X80 pipeline steel welded joints under organic carbon source starvation

Abstract

Sulfate-reducing bacteria (SRB) corrosion of X80 steel welded joint under organic carbon source starvation was investigated in the paper. The results showed that the number of planktonic cells is much less than that of sessile cells after 720 h immersion. The number of sessile cells in the base metal (BM) in the medium with 1% carbon source is the largest. Starving SRB cells accelerated simultaneously the uniform corrosion and localized corrosion of the welded joints, and the acceleration effect on the latter was much higher than that of the former. In all mediums, the density and average depth of pits in the BM and weld zone (WZ) were much larger than those in the heat affected zone (HAZ). SRB corrosion of the welded joint was strongly selective, and organic carbon source starvation further enhanced the selectivity.

The Role of Metallurgical Features in the Microbially Influenced Corrosion of Carbon Steel: A Critical Review

“…Work on and reports of the MIC of carbon and low-alloy steel welds are definitely less comprehensive and less conclusive when compared to the work published on stainless-steel welds [84,85,108,[220][221][222][223][224][225][226][227]. In addition, a wide variety of test configurations have been used, making it very difficult to compare results or determine trends.…”

“…In addition, a wide variety of test configurations have been used, making it very difficult to compare results or determine trends. Test media range from natural seawater [220,221,225] to microbiological growth media containing SRB [222][223][224]226]. Various types of welded sample configurations have been used in research studies, including samples that encompass complete weld samples, i.e., the base metal, the HAZ, and the weld in one sample.…”

“…Although there are potential advantages to each of these different test configurations, it makes comparisons very challenging. The MIC test results are split roughly in half between those that indicate increased corrosion of weld regions [84,85,220,221,225] and those that show that the base metal has greater levels of pitting attack when compared to the HAZ and weld zone [222][223][224]226]. Tests on microbiological attachment also show mixed results, with some tests indicating increased microbial attachment in the weld zone [84,85,226], while others showed greater attachment on the base metal [221,223].…”

Biodegradation of materials: building bridges between scientific disciplines

“…A more classical-albeit insightful-approach that is well represented in the present collection consists of incubating materials with relevant bacterial and/or fungal strains to quantify their contribution to material degradation [12][13][14][15][16][17][18] . This approach is preferentially used to shed light on the mechanisms and chemical fluxes associated with materials biodegradation, and may open new avenues to develop, in turn, methods that may rely on microbial activity to prevent materials from their (bio)degradation 6,19,20 .…”