| Project/Area Number |
11450282
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Metal making engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
MIZOGUCHI Shozo Institute for Advanced Materials Processing, Tohoku Univ., Prof., 素材工学研究所, 教授 (90311555)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAJIMA Keiji Institute for Advanced Materials Processing, Tohoku Univ., Assoc.Prof., 素材工学研究所, 助教授 (40312649)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥15,000,000 (Direct Cost: ¥15,000,000)
Fiscal Year 2000: ¥5,100,000 (Direct Cost: ¥5,100,000)
Fiscal Year 1999: ¥9,900,000 (Direct Cost: ¥9,900,000)
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| Keywords | "Oxide Metallurgy" / "In-situ" observation / Oxide inclusions / Agglomeration / Marangoni convection / Manganese sulfide / Precipitation / Laser microscope / 凝集挙動 / 結晶粒界 |
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| Research Abstract |
Aiming at the development of a new method to make a fine distribution of nanometer size inclusion, "in-situ" observation of agglomeration and precipitation of inclusions was carried out at high temperature. The results are summarized as follows :
1. The attractive force between oxide inclusions was measured. It was revealed that the attractive force was affected strongly by the size, the shape of inclusions and the contact angle between inclusion and molten steel. If the size and the shape of each inclusions were the same, the attractive force of alumina was much stronger than that of magnesia or other particles like liquid inclusions. Based on the theory of capillary interaction between inclusion, it was possible to calculate the attractive force quantitatively using a "shape factor." The calculation results agreed well with the experimental data. So a principle was found to make a fine distribution of inclusions.
2. Marangoni convection was investigated by "in-situ" observation and num
… More
erical simulations. It was revealed that not only thermocapillary convection but solutocapillary convection play an important role to cause some peculiar flow patterns in front of the solid/liquid interface. Oxygen content in molten steel could significantly affect Marangoni convection.
3. The behavior of entrapment of an oxide inclusion at the solidification interface was investigated. It was confirmed that the behavior of pushing and entrapment was controlled by the solidification rate and the inclusion size. When the grain boundaries were moving after solidification, the pinning of one grain boundary by an inclusion could suppress the neighboring boundary to move.
4. The effects of phase transformation on the MnS precipitation was investigated in Fe-Si alloys. It was revealed that the number of inclusions and the temperature at which MnS precipitation started changed according to the phase transformation in alloys. The effects of the matrix phase on the precipitation and the growth of MnS were also studied. It was shown that in δ phase the number of precipitates was much larger and the growth rate of MnS was faster than in γ phase. Less
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