| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2014: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2013: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
|
|---|
| Outline of Final Research Achievements |
The defect behavior in fatigued stainless steel AISI316 was investigated by positron annihilation spectroscopy. The comparison between the positron lifetime results and stress amplitude leadｓ to the conclusion that positron lifetime is sensitive to the change of plastic strain amplitude during the fatigue deformation. The plastic strain amplitude during fatigue deformation is considered to be affected by defects introduced by fatigue deformation. In order to investigate the contribution of vacancy-cluster, the fatigue behavior in the presence and the absence of vacancy-clusters was examined by interrupting the fatigue test and annealing. It is shown that fatigue behavior is significantly affected by the mechanical property change, especially the proof stress, due to the introduction of defects, including vacancy-cluster, during fatigue deformation.
|
