The effects of sulfate reducing bacteria on stainless steel and Ni-Cr-Mo alloy weldments
- Univ. of Virginia, Charlottesville, VA (United States). Center for Electrochemical Science and Engineering
Previous research in this laboratory demonstrated a direct correlation between alloy composition and corrosion susceptibility of stainless steel and Ni-Cr-Mo alloy weldments exposed to lake water augmented with sulfate reducing bacteria (SRB). It was shown that lake water containing an active SRB population reduced the polarization resistance (R{sub p}) on all alloys studied including those with 9% Mo. In addition, preliminary evidence indicated that edge preparation and weld heat input were also important parameters in determining corrosion performance. This prior research, however, looked at ``doctored`` weldments in which the thermal oxide in the heat affected zone was removed. The objectives of the research presented here are to further confirm these observations using as-received welds. The materials examined (listed in increasing alloy content) are 1/4 inch thick plates of 316L, 317L, AL6XN (6% Mo), alloy 625 clad steel, alloy 625, and alloy 686. Materials were welded using the tungsten inert gas (TIG) process in an argon purged environment. In addition, 317L was welded in air to test oxide effects. All samples were prepared for welding by grinding to a V-edge, except the 625 clad steel samples which were prepared using a J-edge. Electrochemical performance of welded samples was monitored in four glass cells which could each allow exposure of 8 samples to the same environment. Two cells contained lake water inoculated with SRS, and two cells contained sterilized lake water. The open circuit potential (E{sub oc}) and R{sub p} was used to correlate corrosion susceptibility and bacterial activity with alloy composition and welding parameters.
- OSTI ID:
- 106154
- Report Number(s):
- CONF-950304-; TRN: IM9542%%242
- Resource Relation:
- Conference: Corrosion `95: National Association of Corrosion Engineers (NACE) international annual conference and corrosion show, Orlando, FL (United States), 26-31 Mar 1995; Other Information: PBD: 1995; Related Information: Is Part Of Corrosion/95 conference papers; PB: 5788 p.
- Country of Publication:
- United States
- Language:
- English
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