Mechanism of hydrogen embrittlement in martensitic steels
| Project/Area Number |
15H04158
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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/Microstructural control engineering
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| Research Institution | Kyoto University |
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Principal Investigator |
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| Research Collaborator |
MOMOTANI yuji
YONEMURA takashi
TAKEDA yasunari
OKADA kazuho
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| Project Period (FY) |
2015-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥16,770,000 (Direct Cost: ¥12,900,000、Indirect Cost: ¥3,870,000)
Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2016: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000)
Fiscal Year 2015: ¥10,530,000 (Direct Cost: ¥8,100,000、Indirect Cost: ¥2,430,000)
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| Keywords | 水素脆性 / マルテンサイト鋼 / 構造材料 / 材料組織 |
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| Outline of Final Research Achievements |
The present project investigated hydrogen-related fracture behavior of martensitic steels by microstructure analysis, three-dimensional fracture surface topography analysis, and hydrogen micro-print technique. The main obtained results are (i) formation site of hydrogen-related cracks is around prior austenite grain boundary in martensite structure, (ii) fracture mechanism changes from plastic strain-controlled to stress-controlled with increasing hydrogen content, (iii) with the proceeding of fracture, the fracture mode changes from intergranular to quasi-cleavage, (iv) hydrogen tends to accumulate around prior austenite grain boundary by tensile deformation at a slow strain rate, (v) hydrogen transportation by dislocation motion is a main mechanism for hydrogen accumulation.
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| Academic Significance and Societal Importance of the Research Achievements |
水素脆性破壊の素過程に関しては，古くから多くの研究がなされてきているが，その破壊メカニズムの解明には至っていないのが現状であった．本研究では，典型的な高強度鉄鋼材料であるマルテンサイト鋼を研究対象とし，マルテンサイト鋼における水素脆性破壊の「破壊起点」，「破壊伝播経路」，「破壊過程における水素集積挙動」を系統的に調べることによって，破壊メカニズムを明らかにした．本研究で得られた結果は水素脆性破壊の理解を大きく進めるものであるだけでなく，水素脆性を抑制するための材料組織制御法に繋がるため，耐水素脆性に優れた材料開発を通して，安全・安心な社会を構成するための社会基盤の構築に貢献しうるものである．
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Report
(5 results)
Research Products
(42 results)
