1989 Fiscal Year Final Research Report Summary
Ultra-Fine Grain Steel Produced by Carbide Dispersion Carburizing Process
| Project/Area Number |
62850129
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
金属材料(含表面処理・腐食防食)
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
NISHIZAWA Taiji Faculty of Engineering, Tohoku University Professor, 工学部, 教授 (60005212)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAHARA Gyozo Iwate Iron Making Co., Managing Director, 技術担当 常務取締役
KAMATA Shin-ichi Mining College, Akita University Research Associate, 鉱山学部, 助手 (50006673)
KOKUBUN Teruhiko Faculty of Engineering, Tohoku University Research Associate, 工学部, 助手 (30205364)
ISHIDA Kiyohito Faculty of Engineering, Tohoku University Associate Professor, 工学部, 助教授 (20151368)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Carburizing / Carbide Dispersion / Grain Refinement / Abrasion Resistance / High Strength Steel / High Speed Steel / Laminated Composite |
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| Research Abstract |
The C-D carburizing-- carburizing treatment for obtaining dispersed carbide particles -- has been tried on several kinds of steel to produce ultra-fine grain steels. The results obtained are summarized as follows :
1. Function of Alloying Elements in C-D Steel Vanadium is the most profitable element to realize the fine dispersion of carbides, because it has a large solubility, while the V-carbide has a much less solubility to the Fe-matrix. Cr, Mo, W and Co are effective to improve the secondary hardening and abrasive resistance. On the basis of these preliminary experiments, the composition of steel was chosen as 7%V, 2%Cr, 4%Mo, 3%W and 5%Co.
2. Mechanical Properties of C-D Steel The results of mechanical tests on the above-mentioned steel are as follows; (1) tensile strength; 1.8GPa, (2) Vickers hardness;950- 1000, (3) abrasion resistance is better then the commercial high speed steel, and (4) bending strength; 3.4 GPa. These values indicate that the,C-D steel is superior in both the strength and ductility, which is mainly due to the ultra-fine grain structure.
3. Practical Use The C-D steel is expected to be useful to thin parts,i.e.,fine cutters, fine drills, pins for dot-printing and so on. The examination of applicability will be carried on from the both sides of technical and economical points.
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