Effect of Carbon Content and Post-Sintering Cooling Rate on Mechanical Properties of Fe-Ni-Cu-Mo-C High Density Sintered Steel

Abstract:

Powders-based on the Fe-Cu-Ni-Mo system are well known in the P/M industry for combining good compressibility and dimensional stability with a potential for high strength. The typical heterogeneous microstructure of these materials has proven to provide favourable mechanical properties. However, in applications where strength and hardness become critical variables, faster cooling rates after sintering are required to meet application requirements. Test specimens containing various graphite contents to achieve 0.20, 0.35 and 0.55% combined carbon were pressed to 7.0 and 7.2 g/cm3, sintered in a furnace at 1150°C and cooled directly from sintering temperature with either normal or rapid cooling. Test results are discussed in terms of tensile properties, apparent hardness and microstructure. The formation of bainite and martensite by raising carbon content and cooling rate increased tensile strength and apparent hardness, while a higher green density maintained satisfactory ductility. It was possible to achieve ultimate tensile and yield strengths as 920 and 660 MPa respectively with apparent hardness 30 HRC.

• Periodical: Advanced Materials Research (Volume 23)
• Pages: 79-82
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.23.79
• Online since: October 2007
• Authors: R. Ivănuş, Liviu Brânduşan
• Keywords: Alloyed Powder, Carbon Content, Post-Sintering Cooling, Sintered Steel

References

[1] A.B. Davala, A.H. Graham and R.J. Causton: Advances in Powder Metallurgy & Particulate Materials, Vol. 2, Part 14, (1997), 81.

[2] U. Engstrom and C. Lindberg, in: Proceeding of Powder Metallurgy World Congress, (1993), 751.

[3] M. Khaleghi and R. Haynes: Powder Metallurgy, Vol. 28, (1985), p.217.

[4] I. Bertilsson and B. Karlsson: Powder Metallurgy, Vol. 30, (1986), p.183.

[5] F. Chagnon and Y. Trudel, Advances in Powder Metallurgy & Particulate Materials, Vo1. 2, Part 14, (1997), p.97.

[6] R.C. Ivanus, I. Pascu, S. Sontea, Proc. Int. Conf. RoPM 2000, Cluj-Napoca, Romania, Vol. 1, (2000), pp.153-100 µm 100 µm.