| Budget Amount *help |
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2015: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
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| Outline of Final Research Achievements |
Hydrogen concentrating around a crack tip significantly accelerates crack propagation, i.e., hydrogen embrittlement. In order to clarify the mechanism leading to this, the local hydrogen concentration behavior, i.e., at a crack tip, was evaluated by numerical analysis and experimental measurements. Although thermal desorption analysis can be used to evaluate the total hydrogen content in metals, it cannot be applied to local areas. Microprint methods, which use chemical reactions between hydrogen and coated elements cannot quantitatively evaluate the hydrogen content. The present study takes account of hydrogen-induced strain, and X-ray diffraction in a confined area was employed to detect variations in lattice spacing before and after hydrogen charging. Using X-ray diffraction applied to a small area, it was demonstrated that the hydrogen concentrates in the vicinity of the crack, i.e., at the elastic-plastic boundary.
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