| Project/Area Number |
17K06051
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Shinshu University |
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Principal Investigator |
NIU LIBIN 信州大学, 学術研究院工学系, 准教授 (20262694)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2017: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | 腐食 / ボイラ水 / 蒸気タービン材料 / 有機酸 / 塩化物イオン / 不働態皮膜 / 孔食 |
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| Outline of Final Research Achievements |
The effect of organic acids (formic acid and acetic acid) in simulated boiler water containing typical corrosive impurities of chloride ions on the corrosion behavior of low-pressure steam turbine materials was investigated using various corrosion tests and surface analyses. For 13Cr stainless steel of blade materials, the formic acid and acetic acid in chloride-containing boiler water showed suppression behavior of localized corrosion such as pitting corrosion. However, for 3.5NiCrMoV steel of rotor materials, formic acid in chloride-containing boiler water promoted corrosion in long-term corrosion tests, while acetic acid exhibited no obvious influence of accelerating corrosion. Based on the analysis results of the film formed on the material surface, the mechanism of influence of organic acids on the corrosion behavior of steam turbine materials was discussed.
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| Academic Significance and Societal Importance of the Research Achievements |
火力発電プラントボイラ給水・補給水には、ボイラなどの腐食や固形析出物によるスケール生成・堆積を防止するために、経験や実験データに基づき、アンモニアが代表的なpH調整用添加薬剤として使用されてきた。近年では、有機アミン類水処理薬剤を採用する傾向が見られている。しかしながら、国内外を問わず有機アミンの生成物として有機酸がプラント機器に与える影響などに関する基礎知見は不足している。低圧蒸気タービン材料の腐食挙動および不働態皮膜の形成と破壊に及ぼすこれらの有機酸の影響に関して、本研究の成果は火力発電プラントの信頼性確保などに貢献できる。
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