Effect of cooling rates on sinter-hardened steels

• Autorzy: Dobrzański L. A. , Musztyfaga M.
• Języki publikacji: EN

Abstrakty

EN

Purpose: Purpose of this paper was to evaluate the differences between rapid, medium and low cooling rates on three systems and also to study cooling mechanism of known materials. Design/methodology/approach: Two different systems have been tested in order to investigate how the cooling rates influence on the microstructure and properties. The powders used in the present invention are pre-alloyed iron-base powders containing low amounts of chromium and molybdenum. The amount of graphite that was admixed to the iron-base powder was 0.6% and lubricant 0.75%. The amount of graphite which is mixed with the iron-base powder is 0.6% and lubricant is 0.75%. Green compact were sintered in a vacuum furnace at 1120şC for 30 minutes in vacuum atmosphere and rapidly cooled in nitrogen with three different rates: rapid cooling (7şC/s) and medium cooling (1.6şC/s), slow cooling (0.3şC/s). Next the samples were tempered in vacuum in the same furnace at 200şC for 60 minutes and then were cooled to room temperature in nitrogen, with the exception of slow cooling cycle. Findings: The effect of cooling and applied sintering were studied in terms of mechanical properties, hardness and wear resistance. The results achieved after the investigation sinter-hardened steels with low carbon content proved that applied process of sintering and different cooling rates brought expected outcome. Practical implications: According to the powders characteristic, the applied rapid and medium cooling rate seems to be a good compromise for mechanical properties and microstructure, nevertheless further tests should be carried out in order to examine different cooling rates. Originality/value: The effect of cooling rates on mechanical properties of pre-alloyed Astaloy CrL and CrM powders was investigated.

Słowa kluczowe

EN

powder metallurgy; sintering; sinter-hardening

PL

metalurgia proszków; spiekanie; utwardzanie poprzez spiekanie

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2009
• Tom: Vol. 37, nr 2
• Strony: 630--638
• Opis fizyczny: Bibliogr. 30 poz., rys., tabl.

Twórcy

autor

Dobrzański L. A.

autor

Musztyfaga M.

• Division of Materials Processing Technology, Management and Computer Techniques in Materials Science, Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, 44-100 Gliwice, Poland,

Bibliografia

• [1] The ASM Powder Metallurgy Committee, Metals Handbook, 9 edition, 7, 1984, 9.
• [2] http://epma.autotrain.org
• [3] A. Salak, Ferrous powder metallurgy, Cambridge International Science Publishing, England 1995, 45-46.
• [4] K. S. Narasimhan, Sintering of powder mixtures and the growth of ferrous powder metallurgy, Materials Chemistry and Physics, 67 (2001) 56-65.
• [5] M. C. Baran, A. H. Graham, A. B. Davala, R. J. Causton, C. Schade Hoeganaes Corporation, A superior sinter-hardenable material, International Conference on Powder Metallurgy and Particulate Materials 20-24 (1999) 1-19.
• [6] G. H. Rutz, A. H. Graham, A. B. Davala, Sinter-hardening P/M. steels, Proceedings of the International Conference on Powder Metallurgy and Particulate Materials, Chicago 1997.
• [7] L. A. Dobrzański, J. Otręba, M. Actis Grande, M.Rosso, Sinter-hardening of Ni-Mo pre-alloyed powders with tungsten addition, Jurnal of Achievements in Materials and Manufacturing Engineering, 20/1-2 (2007) 427-430.
• [8] M. L. Marucci, G. Fillari, P. King, K. S. Sim Narashiman, Sintering a path to cost-effective hardened parts, Metal Powder Report 60 (2005) 42-46.
• [9] L. A. Dobrzański J. Otręba, M. Actis Grande, M.Rosso, Sinter-hardening of Ni-Mo-W steels and their properties, Archives of Materials Science and Engineering 28/2 (2007) 77-82.
• [10] L. A. Dobrzański, J. Otręba, M. Actis Grande, M.Rosso, Microstructural characteristic and mechanical properties of Ni- Mo-(W) steels, Journal of Achievements in Materials and Manufacturing Engineering 18/1-2 (2006) 347-350.
• [11] E. Akpan, Sinter-hardening PM materials and nature of process, Industrial Heating 61/5 (1994) 41-43.
• [12] B. Llindsley, T. Murphy, Dimensional precision in sinter-hardening PM steels, Materials Science Forum, 534-536/1, (2007), 665-8.
• [13] S. St-Laurent, P. Lemieux, S. Pelletier, Behavior of sinter hardening powders during sintering, Proceedings of the International Conference on Powder Metallurgy and Particulate Materials 10, 2004, 145-159.
• [14] G. H. Rutz, H. A. Graham, B. A. Davala, Sinter-hardening P/M. steels, Advances in Powder Metallurgy and Particulate Materials 1 (1997) 8-3-8-20.
• [15] L. A. Dobrzański, J. Hajduczek, A. Kloc-Ptaszna, Effect of the sintering parameters on structure of the gradient tool materials. Journal of Achievements in Materials and Manufacturing Engineering 36/1 (2009) 33-40.
• [16] Z. Brytan, L. A. Dobrzański, M. Actis Grande, M. Rosso, Characteristics of vacuum sintered stainless steels, Journal of Achievements in Materials and Manufacturing Engineering 33/2 (2009) 126-134.
• [17] G. Matula, K. Golombek, J. Mikula, L. A. Dobrzański, Structure of sintered gradient tool materials, Journal of Achievements in Materials and Manufacturing Engineering 32/1 (2009) 23-28.
• [18] R. Yilmaz, M. R. Ekici, Microstructural and hardness characterisation of sintered low alloyed steel, Journal of Achievements in Materials and Manufacturing Engineering 31/1 (2008) 23-28.
• [19] G. Matula, L. A. Dobrzański, A. Varez, B. Levenfeld, Development of a feedstock formulation based on PP for MIM of carbides reinforced M2, Journal of Achievements in Materials and Manufacturing Engineering 27/2 (2008) 195-198.
• [20] L. A. Dobrzański, Z. Brytan, M. Rosso, Sinter-hardening process applicable to stainless steels, Journal of Achievements in Materials and Manufacturing Engineering 24/2 (2007) 11-18.
• [21] L. A. Dobrzański, A. Kloc-Ptaszna, G. Matula, J. M. Contreras, J. M. Torralba, The impact of production methods on the properties of gradient tool materials, Journal of Achievements in Materials and Manufacturing Engineering 24/2 (2007) 19-26.
• [22] L. A. Dobrzański, A. Kloc-Ptaszna, G. Matula, J.M. Torralba, Structure and properties of gradient tool materials with the highspeed steel matrix, Journal of Achievements in Materials and Manufacturing Engineering 24/2 (2007) 47-50.
• [23] G. Matula, L. A. Dobrzański, G. Herranz, A. Varez, B. Levenfeld, J. M. Torralba, Structure and properties of HS6-5-2 type HSS manufactured by different P/M methods, Journal of Achievements in Materials and Manufacturing Engineering 24/2 (2007) 71-74.
• [24] L. A. Dobrzański, J. Otreba, Z. Brytan, M. Rosso, Utilisation of sinter-hardening treatment for various sintered steels, Journal of Achievements in Materials and Manufacturing Engineering 24/2 (2007) 187-190.
• [25] M. Rosso, Contribution to study and development of PM stainless steels with improved properties, Journal of Achievements in Materials and Manufacturing Engineering 24/1 (2007) 178-187.
• [26] L. A. Dobrzański, A. Kloc-Ptaszna, A. Dybowska, G. Matula, E. Gordo, J.M. Torralba, Effect of WC concentration on structure and properties of the gradient tool materials, Journal of Achievements in Materials and Manufacturing Engineering 20 (2007) 91-94.
• [27] L. A. Dobrzański, Z. Brytan, M. Actis Grande, M. Rosso, Influence of sintering parameters on the properties of duplex stainless steel, Journal of Achievements in Materials and Manufacturing Engineering 20 (2007) 231-234.
• [28] L. A. Dobrzański, Z. Brytan, M. Actis Grande, M. Rosso, Corrosion resistance properties of sintered duplex stainless steel, Journal of Achievements in Materials and Manufacturing Engineering 19/1 (2006) 38-45.
• [29] L. A. Dobrzański, M. Musztyfaga, M. Actis Grande, M. Rosso, Computer aided determination of porosity in sintered steels, Archives of Materials Science and Engineering 38/2 (2009) 103-111.
• [30] M. Rosso, L. A. Dobrzański, J. Otreba, M. Actis Grande, Mechanical properties and microstructural characteristic of sinter-hardened steels, Archives of Materials Science and Engineering 35/2 (2009) 117-124.