2003 Fiscal Year Final Research Report Summary
Superhigh Strengthening and Net Shaping for Sintered Low Alloy Steels by Utilizing the Partial Constituent Gradient Microstructure in MIM Process
Project/Area Number |
13555201
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 展開研究 |
Research Field |
Material processing/treatments
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Research Institution | Kumamoto University |
Principal Investigator |
MIURA Hideshi Kumamoto University, Graduate School of Sci. & Tech., Professor, 大学院・自然科学研究科, 教授 (30117254)
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Co-Investigator(Kenkyū-buntansha) |
MATSUDA Mitsuhiro Kumamoto University, Fac. of Eng., Assistant Researcher, 工学部, 助手 (80332865)
OTSU Masaaki Kumamoto University, Fac. of Eng., Lecturer, 工学部, 講師 (20304032)
KAWAMURA Yoshihito Kumamoto University, Graduate School of Sci. & Tech., Associate Professor, 大学院・自然科学研究科, 助教授 (30250814)
UEMURA Makoto Kumamoto Industrial Research Institute, Researcher, 生産技術部・研究員
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Project Period (FY) |
2001 – 2003
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Keywords | Metal Injection Molding / Sintered low alloy steel / Ni addition / Heat treatment / Mezzo heterogeneous structure / Mechanical properties |
Research Abstract |
Metal Injection molding (MIM) process is an advanced powder processing technique because of net shaping with shape complexity at low processing energy and 100% material utilization. This study has been performed to clarify and to optimize the relationship between the mechanical properties and the microstructures for the superhigh strengthening sintered low alloy steels (Fe-Ni system) by using MIM process. A 6%mass%Ni MIM steel showed excellent properties of 2000MPa tensile strength, 5% elongation, and 500MPa fatigue strength. The Ni rich phase consists of only the martensitic structure if the size of agglomerated Ni powders is below 18μm, whereas the retained austenite is formed in the center of Ni rich phases if the size of agglomerated Ni powders is above 18μm. If the Ni powders of approximately 20μm particle size is dispersed uniformly in the matrix, therefore, superior mechanical properties may be obtained by even the same composition of Fe-6Ni-0.5Mo-0.2Mn steels. Instead of Fe-Ni, moreover, the Fe-Mn low alloy steel was investigated to obtain high performance properties, because Ni has harmful influence upon the human body, for example, a Ni allergy.
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Research Products
(10 results)