Wear Mechanisms in High Speed Steel Gear Cutting Tools

In this paper, the wear of high speed steel hobs during hobbing has been studied. The wear mechanisms are strongly influenced by the choice of cutting speed. At moderate and high cutting speeds three major wear mechanisms were identified: abrasion, mild adhesive and severe adhesive. The microstructure and wear behavior of two high speed steel grades (M2 and ASP30) has been compared. In contrast, a variation in chemical composition or microstructure of HSS tool material generally did not change the dominant wear mechanism. However, the tool material properties determine the resistance against the operating wear mechanism and consequently the tool life. The metallographic analysis and wear measurement at the tip of hob teeth included scanning electron microscopy and stereoscope microscopy. Roughness profilometery is used for measuring the gear surface roughness.

Authors:

• M. Jalali Azizpour
• H. Mohammadi majd

Keywords:

• abrasion
• adhesion
• cutting speed
• hobbing
• wear mechanism

References:

[1] Tokawa, T. and Nishimura, Y., "High productivity dry hobbing system" ,
Mitsobishi Heavy Industry, Technical Review, Vol. 38, No.1,PP. 124-
147, 2001.
[2] Jainlk, C. and Agreval, G., Metal cutting science and production
technology, McGraw - Hill Publishing company, NewDelhi, 1988.
[3] Rech, J. and Djouadi, M. and Picot, J., "Wear resistance of coating in
high speed gear hobbing", Wear, Vol. 250, PP. 45-53, 2001.
[4] Lim, S.C. and Lee, S.H. and Liu, Y.B. "Wear maps for uncoated high
speed steel cutting tools", Wear, Vol. 170, PP.137-134, 1993.
[5] Scherge, M. and shakhvorostove, "Fundamental of wear mechanisms of
metal", Wear, Vol. 255, PP. 395-400, 2003.
[6] Haron, O. and subramanian, S.V., " Tribology of tool-chip interface and
tool wear mechanisms", Surface and Coatings Technology, Vol. 149,
PP. 151-160, 2001.
[7] Soderberg, S. and Hogmark, S., "Wear mechanisms and tool life of high
speed steels related to microstructure", Wear, Vol. 110, PP. 315-329
,1985.
[8] Brion, J.M., "Mechanisms of built-up layer formation on turning tools:
Influence of tool and workpiece", Wear, Vol.154, PP. 225-239, 1992.
[9] Bhattacharyya, A., Metal Cutting Theory and Practice, Jadavpur
University, New Central Book Agancy, Calcutta, 1998.
[10] EL-Rakayby, A. M. and Mills, B., "the role of primary carbides in the
wear of high speed steel",Wear, Vol. 112, PP. 327-340, 1986.
[11] Joseph, R., ASM Handbook,Vol. 16: Machining, American Society for
Metals, 9th Edition, 1998.