| Project/Area Number |
05650710
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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 |
Material processing/treatments
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| Research Institution | Osaka University |
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Principal Investigator |
KURODA Toshio Osaka University, Welding Research Institute, Assistent Professor, 溶接工学研究所, 助手 (00107096)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1993: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Duplex Stainless Steel / Weldment / Hydrogen Measurement Technique / Weld Cracking / Hydrogen Diffusion / Internal Friction Measurement / Numerical differential Calculation / G-BOP Weld Cracking Test / G-Bop試験 / Y-Groove試験 / フィッシュアイ |
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| Research Abstract |
The aims of this investigation is to establish new hydrogen analysis method which can distinguish hydrogen between in the austenite and in the ferrite, and to evaluate the critical hydrogen content not to crack using weld cracking test for various duplex stainless steel and the weldments.
1. Ferralium 255, Alloy 2205 and SUS329J1 steel were employed as base metals, and Ferralium 259, Alloy 2209, SUS329J3L and SUS329J4L were used as the SMAW welding rods. The samples from the base metals and weld metals were heated continuously up to 1973K at various heating rates and hydrogen from the samples was measured at real time. In this new hydrogen analysis technique, hydrogen evolved at lower heating temperature was from the ferrite and hydrogen evolved at higher heating temperature was from the austenite. The distinguish between hydrogen in the ferrite and hydrogen in the austenite could be made.
2. Another new hydrogen analysis technique was developed using an internal friction measurement performed. The internal friction peak at 1.5Hz was observed at 260K,the peak height was related to the hydrogen content in the austenite for duplex stainless steels. The distinguish between hydrogen in the ferrite and hydrogen in the austenite could be made.
3. Hydrogen diffusion behavior in the ferrite and in the austenite was calculated using numerical differential method and the diffusion model was coincident with the experimental results.
4. The relation between hydrogen content and hydrogen cracking characteristics was evaluated using various weld cracking tests, and critical hydrogen content not to crack was determined.
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