1997 Fiscal Year Final Research Report Summary
Development of High Speed Steels with a Fine Grain Size by Carbide Dispersion Carburization (CDC) Process.
| Project/Area Number |
08555160
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Structural/Functional materials
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
KAINUMA Ryosuke Tohoku University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (20202004)
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| Co-Investigator(Kenkyū-buntansha) |
KODAKANE Masaaki Nippon Koshuha Steel Co., R & D Department, Manager of R & D Dept., 技術開発室, 開発室長(研究職)
MACHIDA Masahiro Kobe Steel Ltd., Akashi Factory, Industrial Technology Center, Manager of the Ce, 赤石工場生産技術室, 技術室長(研究職)
OHNUMA Ikuo Tohoku University, Graduate School of Engineering, Research Associate, 大学院・工学研究科, 助手 (20250714)
OHTANI Hiroshi Tohoku University, Center for Interdisciplinary Research, Associate Professor, 学際科学研究センター, 助教授 (70176923)
ISHIDA Kiyohito Tohoku University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (20151368)
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| Project Period (FY) |
1996 – 1997
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| Keywords | CARBRIZATION / STEELS / Fe-V-Mo-C SYSTEM / PHASE DIAGRAM / CDC PROCESS / WEAR RESISTANCE / HIGH SPEED STEEL |
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| Research Abstract |
Recently, a new type of process to fabricate high speed steels consisted of hyperfine grains together with uniformly distributed particles, which is called as carbide dispersion carburization (CDC) process, is proposed. In this process, the superior resistance to wear and the outstanding toughness can be obtained by carburizing C-free Fe base alloys with high contents of Ti, V,Mo, W etc..
In this study, an attempt by CDC process was made to produce high speed steels with very high hardness over Hv1000 on the basis of information of the calculated phase diagrams. The obtained results are as follows :
(1) In order to establish a data base for estimating phase equilibria of the Fe-base multi-component systems, thermodynamic analysis of Fe-C and Fe-N base systems were performed.
(2) On the basis of results of the thermodynamic analysis, microstructural evolution (including the kind, content and volume fraction of carbides appearing during carburizing and heat treatment) of Fe-V-Mo-C alloys was simulated.
(3) Volume fraction, size and distribution of carbides in several Fe-V-Mo-C specimens with different composition produced by CDC process have been measured. The result of the examination suggests that the carbon content and the atomic ratio between V and Mo are the most important factors for determining the size and distribution of carbides.
(4) On the basis of such the calculation and examination for the microstructural control, some alloys with suitable composition for obtaining both high hardness and toughness have been produced and examined. Consequently we could get some excellent alloys with hardness over Hv 1000.
At the present, a cooperation project for practical applications with steel making companies is running.
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