2014 Fiscal Year Final Research Report
Clarification of phase stability of retained-austenite in M-A constituent by crystallographic analysis using synchrotron radiation.
| Project/Area Number |
24560879
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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 |
Material processing/treatments
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| Research Institution | Osaka University |
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Principal Investigator |
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Keywords | 溶接 / 溶接熱影響部 / M-A組織 / き裂 / 有効結晶粒 / じん性 / 相変態 / 高張力鋼 |
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| Outline of Final Research Achievements |
In simulated HAZ of high-strength steel simulating high heat input welding,
it was clarified that phase stability of retained-austenite in M-A constituent was high when it was formed between bainitic ferrite laths of same variant. By using bright X-ray diffraction analysis, the carbon content of stable retained-austenite was quantified as 1.0 mass%. On the other hand, its stability was low when retained-austenite was formed between different variants. Furthermore, to assess the relation among M-A constituent, matrix microstructure and toughness, resistance due to the microstructural factor against cleavage crack extension was visualized using EBSD analysis. For the crack extension, both of Bain zone boundaries and boundaries of close-packed plane group were resistance. Furthermore, M-A constituent easily formed at boundaries of close-packed plane group was also resistance. Those facts were visualized by analyzing the secondary crack extension in simulated HAZ of high-strength steel.
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| Free Research Field |
溶接・接合
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