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Master Alloys to Obtain Premixed Hardenable Powder Metal Steels
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Abstract
Systems of alloys for liquid phase alloying during sintering were investigated. The solidification range of alloys of Mn-Ni-Cr-Mo-Fe and Mn-Cu-Ni was determined. Alloys with the lowest and narrowest melting range were prepared and atomized in nitrogen. Admixtures of master alloys to water-atomized, forging grade, pure iron powder were sintered at 1232°C (2250°F). After hot forging, these P/M steels exhibited hardenabilities which were 75%-90% of theoretical hardenability, as calculated from the factors for conventional steels. Alloying efficiency was further improved to 85%-100% of theoretical hardenability when additions of approximately 2% silicon and 1% rare earth misch-metal were made to the master alloys. The silicon and rare earth misch-metal additions were used to enhance diffusion and sintering. The steels obtained by premixing and sintering master alloys with pure iron powder were substantially homogeneous, had excellent microstructures, and exhibited very good tensile and impact properties. It was observed that molybdenum was the slowest diffusing element of those investigated and that manganese diffused about three times faster than molybdenum. However, it was also noted that the diffusion rate of manganese was slowed to the speed of molybdenum when both manganese and molybdenum were contained in the admixed alloy. It was decided to use a base iron powder which was prealloyed only with molybdenum to counteract the slowing down of manganese diffusion during sintering. Accordingly, an iron alloy powder containing 0.3% Mo admixed with a manganese-rich master alloy doped with silicon and rare earths produced a P/M steel which exhibited alloying efficiency approaching 100%. This led to the conclusion that liquid phase alloying is the best method for producing high density, warm-compacted P/M steels having good hardenability.
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Citation
Mocarski, S., Hall, D., Chernenkoff, R., Yeager, D. et al., "Master Alloys to Obtain Premixed Hardenable Powder Metal Steels," SAE Technical Paper 960388, 1996, https://doi.org/10.4271/960388.Also In
References
- Lenel, F.V. Powder Metallurgy, Principles and Applications Metal Powder Industries Federation Princeton NJ
- Eloff, P.C. Kaufman, S.M. 1971 Hardenability Considerations in Sintering of Low Alloy Powder Powder Metallurgy International 3 71
- Eremko, V.N. Naidich, Y.V. Lavirenko, I.A. 1971 Liquid Phase Sintering: A Special Report Russian Consultants Bureau New York, London
- German, R.M. 1985 Liquid Phase Sintering Plenum Press New York London
- Kingery, W.D. Narasimhan, M. D. 1959 J Appl Phys 31 306
- Albano-Muller, L. Thümmler, F. Zapf, G. 1973 High Strength Sintered Iron-Base Alloys By Using Transition Metal Carbides Powder Metallurgy 16 32 236
- Schlieper, G. Thümmler, F. 1979 High Strength, Heat Treatable, Sintered Steels Containing Manganese, Chromium, Vanadium, and Molybdenum Powder Metallurgy International 11 4
- Retelsdorf, H.J. Fichte, R.M. Hoffman, G. Dalal, K. 1975 Herstellung und Verwendung von Basis Legierungspulvern des Mn-Cr-Mo-Typs Fourth European Symposium for Powder Metallurgy Grenoble
- Hoffman, G. Dalal, K. 1979 Development and Present Situation of Low Alloyed P/M Steels Using MCM and MVM Master Alloys Powder Metallurgy International 11 4
- Zapf, G. Dalal, K. 1977 Introduction of High Oxygen Affinity Elements Manganese, Chromium, and Vanadium in the Powder Metallurgy of P/M Parts Modern Developments in Powder Metallurgy Hausner H.H. Taubenblat P.W 10
- James, B.A. 1985 Liquid Phase Sintering in Ferrous Powder Metallurgy Powder Metallurgy 28 3 121
- James, W.B. Causton, R.J. 1992 Surface-Hardenable Heat Treated P/M Steels. Advances in Powder Metallurgy Proceedings of Powder Metallurgy World Congress MPIF 15 65
- Mocarski, S. 1973 New P/M Steels for Critical Components Metals Engineering Quarterly Nov.
- Mocarski, S. 1976 Hardenable Hot-Formed P/M Steels as a Substitute for Conventional Steels The International Journal of Powder Metallurgy 12 1 47
- Mocarski, S. 1973 Influence of Process Variables on Properties of Mod. 8600 and Manganese-Nickel-Molybdenum Low Alloy Hot Formed P/M Steels Modern Developments in Powder Metallurgy 7 303
- Doane, D.V. 1978 A Critical review of Hardenability Predictors Proceedings of AIME Symposium on Hardenability Concepts with Applications to Steel Doane D.V. Kirkaldy J.S. The Metallurgical Society of AIME Warrendale, PA
- Smith, Y.E. Pathak, R. 1971 New Hardenability Data for Application in Low Alloy Ferrous Forging Proceedings AMPI Fall Powder Metallurgy Conference Mocarski S.
- SAE Standard J406 1993 Methods of Determining Hardenability of Steels June
- Lindskog, P. Grek, S.E. 1973 Reduction of Oxide Inclusions in Powder Metal Preforms Prior to Hot Forming Modern Developments in Powder Metallurgy 7 285
- Mocarski, S. Method of Making Sintered Powder Alloy Compacts
- Shivanath, R. Jones, P.K. High Temperature Sintering: Long-Term, High-Volume Production Experience at Stackpole, LTD. Unpublished Report Stackpole, LTD. Toronto, Ont. L5J 1K7
- McDermott, M.J. 1990 P/M Parts Fabrication Experience with Ancorbond (Binder Treated) Premixes MPIF Conference Proceedings Pittsburgh, PA MPIF
- Gelinas, C. Chagnon, F. Trudel Y. Pelletier, S. 1995 Optimizing Properties of Binder-Treated Ferrous Powder Premixes Proceedings of International Conference of Powder Metallurgy and Particulate Materials Seattle, WA MPIF
- Rutz, H.G. Hanejko, F.G. 1995 High Density Processing of High Performance Ferrous Materials The International Journal of Powder Metallurgy 31 1 9 17
- Chagnon, F. Trudel, Y. 1995 Effect of Compaction Temperature on Sintered High Density Materials Proceedings, International Conference on Powder Metallurgy and Particulate Materials May APMI Princeton, NJ