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Surface layer microhardness changes with high-speed turning of hardened steels

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Abstract

In high-speed cutting of hardened steels, the surface layer is strongly affected by thermal effects and mechanical forces. Due to this, the surface layer of the machined material changes noticeably. Microhardness, one parameter of the surface integrity, is the most important. This paper deals with an investigation of microhardness. Measuring results are presented, and reasons for the sometimes significant changes in microhardness are analysed. It is proved on which part of the cutting edge the material removal will not take place but the cutting edge deforms the material plastically and how this part of the cutting edge can be reduced. With the measurement of the cutting force, the hypothesis is proved that the values of the cutting force components related to each other are different compared to the traditional turning. The passive force is 1.88–2.25 times higher than the main cutting force. Hence, the force taking place on the flank face of the cutting tool is very high and the friction power significantly influences the cutting temperature. The friction taking place on the flank face of the cutting tool generates 2.8–3.9 times higher heat than the cutting force. Due to the changes that occur in the surface layer, the hardness of this layer is higher with 100–150 HV in depth of 0.1 mm than the original hardness or the hardness prescribed in the technical drawings. This phenomenon can be observed not only in internal hard turning but also machining of external and conical surfaces. Microhardness is compared after hard turning and after grinding. According to the measurements, the ground surface has not become a harder surface layer but softer. As an average result of many measurements, it has been proven that the original hardness (700 HV) after case hardening will increase to 800–850 HV after hard turning and will decrease to 500–550 HV after grinding. Microhardness changes are analysed considering the typical chip removal characteristics of hard turning. In this article, the focus is on how changes in microhardness influence the functional behaviour of the components and may affect their lifetimes. In this article, it has been proven that independently from the surface of the machined gear (bore, conical or face surface) the changes in the surface layer regarding microhardness do not differ.

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References

  1. Rech J, Moisan A (2002) Surface integrity in finish hard turning of case-hardened steels application to gear cane brakes. Proc. of the International Conference on Manufacturing Engineering. Haikidiki, pp. 195–203

  2. Abrao AM, Aspinwall DK The surface integrity of turned and ground hardened bearing steel, Wear 196: 279–284

  3. Schmidt J Mechanische und thermische Wirkungen beim Drehen gehärteter Stähle. Berichte aus dem Institut für Fertigungstechnik und spänende Werkzeugmaschine. Universität Hannover Reihe 2. Nr. 519

  4. Wobker HG (1997) Hartbearbeitung, Habilitation thesis. Uni-Hannover

  5. Jaeger JC (1942) Moving sources of heat and the temperature at sliding contact. Proc of the Roy Soc New S Wales 76(3):203–224

    MathSciNet  Google Scholar 

  6. Tönshoff HK, Arendt C, Ben Amor R (2000) Cutting of hardened steel. Annals of the CIRP 49(2):547–566

    Article  Google Scholar 

  7. Schmidt J (1999) Mechanische und thermische Werkungen beim Drehen gehärteter Stähle. PhD Dissertation, Universität Hannover

    Google Scholar 

  8. Kundrák J Bana V (2005) Surface integrity of hardened bores Proc. on the microCAD´2005 International Scientific Conference, Section M: Production Engineering and Manufacturing Systems Miskolc, Hungary, pp. 89–96

  9. Brinksmajer E, Brockhoff T (1994) Randschicht-wärmebehandlung durch schleifen. Härterei-Technische Mitteilungen 49:5327–330

    Google Scholar 

  10. Shaw MC, Vyas A (1994) Heat affected zones in grinding steels. Annals of the CIRP 43(1):279–282

    Article  Google Scholar 

  11. Rose A (1966) Eigenspannung als ergebnis von wärmebehandlung und umwandlungsverhalten. HtM 21(1):150–164

    Google Scholar 

  12. Bana V, Karpuschewski B, Kundrák J, Hoogstrate AM (2007) Thermal distortions in the machining of small bores. J Mater Process Technol 191:335–33

    Article  Google Scholar 

  13. Brinksmeier Brockhoff (1999) White layers in machining steels. 2nd International Conference on High Speed Machining, Darmstadt, pp. 7–13

  14. Tönshoff HK, Karpuschewski B, Borbe C (1998) Hard machining—state of research. Proc. Of the Intern. CIRP/VDI-Conf. High-Performance Tools, Düsseldorf, pp 253–277

    Google Scholar 

  15. Beno J (1999) Teória rezania kovov (Theory of metal cutting) Kosice 250

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Authors and Affiliations

  1. Department of Production Engineering, University of Miskolc, Miskolc, Hungary

    J. Kundrak, K. Gyani & V. Bana

  2. Project Center for Nanotechnology and Advanced Engineering, National Center of Scientific Research “Demokritos”, Athens, Greece

    A. G. Mamalis

Authors
  1. J. Kundrak
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  2. A. G. Mamalis
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  3. K. Gyani
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  4. V. Bana
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Correspondence to J. Kundrak.

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Kundrak, J., Mamalis, A.G., Gyani, K. et al. Surface layer microhardness changes with high-speed turning of hardened steels. Int J Adv Manuf Technol 53, 105–112 (2011). https://doi.org/10.1007/s00170-010-2840-y

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  • DOI: https://doi.org/10.1007/s00170-010-2840-y

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