2013 Fiscal Year Final Research Report
In-situ measurement of stress and solid state phase transformation in low temperature phase transformation weld metal by synchrotron X-ray during welding process
| Project/Area Number |
24760606
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Material processing/treatments
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| Research Institution | Japan Atomic Energy Agency |
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Principal Investigator |
ZHANG shuoyuan 独立行政法人日本原子力研究開発機構, 原子力科学研究部門 量子ビーム応用研究センター, 博士研究員 (00613184)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | 溶接 / 応力 / 固相変態 / その場測定 / 放射光X線 |
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| Research Abstract |
Reduction of welding residual stresses due to introduction of volume expansion via martensitic low temperature phase transformation has received more attention. In order to predict and control the mechanical performance and microstructure of welded structures, it is necessary to clarify the formation mechanism of stress and microstructure during the welding process. Therefore, we developed an in-situ measurement system using synchrotron X-rays, which allows simultaneous measurement of the phase transformation and stress during the welding process. We succeeded in measuring the time variation of the stress distribution and microstructure between the weld metal, heat affected zone, and base material, with the fastest time resolution (0.1 seconds) in the world. By using the in-situ measurement system to observe the entire specimen, we found that stress formation was largely responsible for the solid phase transformation and thermal contraction in the welding continuous cooling process.
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