대한용접접합학회:학술대회논문집 (Proceedings of the KWS Conference)
- 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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- Pages.133-138
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- 2002
ANALYSIS ON MICROBIOLOGICALLY INFLUENCED CORROSION FAILURE CASE OF SUS316L STAINLESS STEEL WELDS
- Miyano, Yasuyuki (Graduate School of Engineering, Osaka University) ;
- Yamamoto, Michiyoshi (Hitachi,Ltd. Power&Industrial Systems, Nuclear Systems Division) ;
- Watanabe, Kazuya (Marine Biotechnology Institute Co. Ltd. Kamaishi Laboratories) ;
- Kikuchi, Yasushi (Joining and Welding Research Institute, Osaka University)
- 발행 : 2002.10.01
초록
Microbiologically Influenced Corrosion (MIC) was suspected in a corrosion failure of cooling system of stainless piping welded joint, carrying marine water. Marine water which is used for cooling water in a plant was transferred to the laboratory and used for experiment. In the first experiment, weld metal samples were exposed to the test solution for 56 days (marine water and sterilized marine water (control)). Surface condition of experimental coupons was observed using a Scanning Electron Microscope (SEM). In another experiment, free corrosion potential of these material was monitored for 56 days. Pitting corrosion was found in the coupons exposed to marine water. Free corrosion potential ennoblement was found to be significant compared to control. It was suspected that this corrosion case was MIC. In the second experiment, coupons were exposed to diluted nutrient medium containing single culture of microbes isolated from the MIC causing marine water sample used for the first experiment. After exposure test, surface condition of experimental coupon was observed using SEM. Pitting corrosion was found in coupons exposed to some of the isolates. The results indicate that they contribute to the corrosive effect of the SUS316L welds.
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