Corrosion of 1020 carbon steel coupons in natural seawater over a six-month period was more aggressive under stagnant anaerobic conditions than stagnant aerobic conditions as measured by weight loss and instantaneous corrosion rate (polarization resistance). Under oxygenated conditions, a two-tiered oxide layer formed. The outer oxide layer was reddish-brown and contained numerous filamentous bacteria. The inner oxide was extremely tenacious and resistant to acid-cleaning. Under anaerobic conditions, a non-tenacious sulfur-rich corrosion product with enmeshed bacteria formed on carbon steel surfaces. In both aerobic and anaerobic exposures, corrosion was more aggressive on horizontally oriented coupons compared to vertically oriented samples. Bulk water chemistry and microbial populations were measured as a function of time. Despite the stagnant conditions, both were dynamic.

Subject
Water, Iron sulfides, Sulfates, Metal coupons, Natural seawater, Seawater, Biofilms, Corrosion products, Oxygen, Carbon steel, Sulfides, Corrosion coupons, Electrodes
Keywords:
Carbon steel, microbiologically influenced corrosion, sulfate-reducing bacteria, seawater, anaerobic
Government work published by the Association for Materials Protection and Performance (AMPP) with permission of the author(s). Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2004
GOV
You do not currently have access to this content.