| Project/Area Number |
62550082
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
材料力学
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| Research Institution | Sophia University |
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Principal Investigator |
NOZUE Akira (1988) Sophia University, Faculty of Science and Technology, Associate Prof., 理工学部, 助教授
大久保 忠恒 (1987) 上智大学, 理工学部, 教授 (60010774)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Hiroshi Sophia University, Faculty of Science and Technology, Assistant, 理工学部, 助手 (30154579)
白砂 洋志夫 上智大学, 理工学部, 助手 (90053652)
OKUBO Tadatsune Sophia University, Faculty of Science and Technology, Prof., 理工学部, 教授 (60010774)
SHIRASUNA Yoshio Sophia University, Faculty of Science and Technology, Assistant
野末 章 上智大学, 理工学部, 助教授
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1988: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Titanium Alloy / Hydrogen Embrittlement / 組織制御 |
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| Research Abstract |
A better understanding is required to identify the effects of the Ti-6Al-4V alloy structure on hydrogen embrittlement behavior. Microstructural factors appear to be the volume ratio of primary alpha phase to the matrix phase consisting of retained beta martensite, the structures of the matrix phase, the configuration of the matrix phase, and the primary alpha grain size. The purpose of the present study is to clarify the effects of these structures on the hydrogen embrittlement behavior.
Compact tension specimens were cathodically charged in a 50 mol/m^3 H_2SO_4 solution under the condition of a current density of 2kA/m^2 during sustained loading. No aging treatment was carried out to simplify the structures. The time to a given creck growth length was evaluated as the susceptibility to the hydrogen embrittlement on stage ll in the relation between crack growth rate and stress intensity factor, by eliminating the region of unstable crack growth and initial creck growth.
The susceptibility to the hydrogen embrittlement of the present alloy is found to be enhanced by the increase in the volume ratio of the primary alpha phase to the matrix phase, the continuity of the beta phase,and the multiplication of the primary alpha grain size.
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