1997 Fiscal Year Final Research Report Summary
Microbially Influenced Corrosion of various types of stainless steel welds and joints.
| Project/Area Number |
08455336
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Material processing/treatments
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| Research Institution | Osaka University |
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Principal Investigator |
KIKUCHI Yasushi Joining and Welding Research Institute Osaka University, Professor, 接合科学研究所・再帰循環システム研究センター, 教授 (90005405)
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| Project Period (FY) |
1996 – 1997
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| Keywords | bacterial corrosion / stainless steel / welds / 金属と微生物 |
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| Research Abstract |
The failure in the weld joint occurred in as little as, two months from the start-up of the sewage treatment plant. At the beginning of the failure analysis, crevice corrosion was considered as the main reason since the welding defects. But, the estimated corrosion rate of the welds was too fast. Then, metallurgical failure analysis to understand this behavior was carried out. Finally, it was concluded that the localized corroion on the welds was a kind of Microbiologically Influenced Corrosion (MIC).
The first stage of a laboratory scale test using the stainless steel welds and the residual liquid obtainable from the MIC-affected effluent treatment plant was performed.
The test samples were exposed in the liquid and kept in an incubator at constant temperature. Corrosion pits were found on 316L,308N (0.2% mass nitrogen approximately) and 308 weld metal. The colonies of bacteria several mum in size near the corrosion pits were observed and the types of the bacteria was identified. The evaluation test of corrosion ability of the identified bacteria was planned. MIC susceptibility of the stainless steels used was evaluated.
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Research Products
(24 results)
