| Project/Area Number |
04555161
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属加工(含鋳造)
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| Research Institution | The University of Tokyo |
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Principal Investigator |
UMEDA Takateru The Univ.of Tokyo Faculty of Engineering, Professor, 工学部, 教授 (50011078)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAJIMA Keiji Sumitomo Metal Industries Iron & Steel Research Laboratories, Researcher, 研究員
IKEDA Minoru The Univ.of Tokyo Faculty of Engineering, Research Associat, 工学部, 助手 (50167243)
中島 敬治 住友金属(株), 鉄鋼技術研究所, 研究員
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥11,100,000 (Direct Cost: ¥11,100,000)
Fiscal Year 1993: ¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 1992: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Keywords | Carbon steel / Cu-(2-8%)Sn alloys / High temperature deformation / Zero Strength Temperature (ZST) / Zero Ductility Temperature (ZDT) / Solid-liquid coexisting temperature / 固液共存 / 強度 / 延性 / デンドライト / ひずみ速度 / ミクロ偏析 / MnS |
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| Research Abstract |
For metals processings which aim at higher quality and higher productivity, solidification crack is one of the worst obstruction variables to overcome. Therefore we investigated the deformation behavior of carbon steels and copper-tin alloys during and after solidification. We carried out high temperature tensile tests for samples which have higher carbon contents to 0.8wt% and for samples which have higher sulfur contents. We also investigated the influence of strain rate on mechanical properties during solidification of 0.6wt%C samples. As a result of the high temperature tensile test, ZST(Zero Strength Temperature) was determined to be the temperature which corresponds to the solid fraction of about 0.7 for both high carbon samples and high sulfur samples as is same with the previous experimental results. On the contrary little ductility was observed even below the temperature at which solidification completes according to the numerical analysis, and ZDT could not be determined. The reason why ZDT does not correspond to the solid fraction of 1 seems to be the low purity of the samples compared with the previously tested samples. For example, having both sulfur and phosphorus are more contained for about. However the mechanism of causing the ZDT drop remains unexplained. The increase of strain rate gave rise of the tensile strength, and around 5mm displacement was measured under strain rate of 10^<-3>/s though little displacement was observed under strain rate of 10^0-10^<-2>/s. Consequently it is concluded that the mechanical properities depend on the strain rate even in the solidification temperature range.
As for copper-tin alloys deformation behavior under strain tate of 10^0-10^<-4>/s was measured at the temperature range below the solidus. Regression equations for tensile strength, flow stress and elongation are obtained in relation to testing temperature, strain rate and/or strain.
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