A machinability evaluation based on the thermal and mechanical properties of two engine valve steels

Abstract

Iron-based superalloys are difficult to machine because of their thermal and mechanical properties provided by alloying elements as nickel, chromium, titanium, and aluminum. However, parts made with this kind of material has to be machined during their production processes. In this work, two different automotive engine valve steel grades, VAT 30® and VAT 36®, were compared in terms of machinability, considering cutting power consumption, roughness of the machined surface, and tool life, besides the identification of the main tool wear mechanisms that have led to the end of tool life. The main goal of this work is to understand the difference in these machining outputs based on the thermal and mechanical properties of these two materials. In order to reach this goal, turning tests were held using two different cooling conditions, conventional and high-pressure coolant. Also, two PVD-coated carbide inserts were applied, one with negative rake angle and another neutral. Finally, cutting speed was tested in two levels, providing a full 24 factorial planning. Results show that VAT 30® has shown higher machinability in terms of tool life in almost every condition, although this steel presents higher hardness, mechanical strength, and strain hardening coefficient, besides lower thermal conductivity. However, it also presents lower ductility and abrasiveness, features that retarded abrasion and attrition as tool wear mechanisms, in such a way that tool life could have been lengthened.

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References

  1. 1.

    Pierce D et al (2019) High temperature materials for heavy duty diesel engines: historical and future trends. Prog Mater Sci. https://doi.org/10.1016/j.pmatsci.2018.10.004

  2. 2.

    Farina AB, Liberto RCN, Barbosa CA (2013) Desenvolvimento de novos aços válvula para aplicação em motores de alto desempenho. Tecnol Metal Mater Min. https://doi.org/10.4322/tmm.2013.043

    Book  Google Scholar 

  3. 3.

    Silva ALVC, Mei PR (2006) Aços e Ligas Especiais. Blucher, São Paulo

    Google Scholar 

  4. 4.

    Ezugwu EO (2005) Key improvements in the machining of difficult-to-cut aerospace superalloys. Int J Mach Tool Manu. https://doi.org/10.1016/j.ijmachtools.2005.02.003

  5. 5.

    Zimmerman C, Boppana SP, Katbi K (1990) Machinability test. In: Metals handbook,v. 16, 10th edn. ASM International, Metals Park, pp 639–647

    Google Scholar 

  6. 6.

    Yamane Y, Sekyia K, Narutaki N, Ezugwu EO (2006) Difficulty in machining calculated from mechanical and thermal properties of difficult to cut material. Int C Prog Mach Technol 8:497–501

    Google Scholar 

  7. 7.

    Stahl JE et al (2012) Metal cutting theories and models. Lund University Press. In: Lund

    Google Scholar 

  8. 8.

    Asha PB et al (2018) Effect of machining parameters on cutting tool temperature and tool life while turning EN24 and HCHCr grade alloy steel. Mater Today-Proc. https://doi.org/10.1016/j.matpr.2018.02.152

  9. 9.

    Vinoth Jebaraj A et al (2017) Weldability, machinability and surfacing of commercial duplex stainless steel AISI2205 for marine applications - A recent review. J Adv Res. https://doi.org/10.1016/j.jare.2017.01.002

  10. 10.

    Denkena B et al (2015) Effects of alloying elements in UHC-steels and consequences for the machinability. CIRP J Manuf Sci Technol. https://doi.org/10.1016/j.cirpj.2015.04.001

  11. 11.

    Rocha CA et al (2004) Evaluation of the wear mechanisms and surface parameters when machining internal combustion engine valve seats using PCBN tools. J Mater Process Technol. https://doi.org/10.1016/j.jmatprotec.2003.10.004

  12. 12.

    Liu G et al (2017) The modified surface properties and fatigue life of Incoloy A286 face-milled at different cutting parameters. Mat Sci Eng Struct. https://doi.org/10.1016/j.msea.2017.07.072

  13. 13.

    Tian X et al (2018) Performance of Si3N4/(W, Ti)C graded ceramic tool in high-speed turning iron-based superalloys. Ceram Int. https://doi.org/10.1016/j.ceramint.2018.05.222

  14. 14.

    Davoodi B, Eskandari B (2015) Tool wear mechanisms and multi-response optimization of tool life and volume of material removed in turning of N-155 iron–nickel-base superalloy using RSM. Measurement. https://doi.org/10.1016/j.measurement.2015.03.006

  15. 15.

    Ferraresi D (1970) Usinagem dos metais. Blucher, São Paulo

    Google Scholar 

  16. 16.

    Buttery TC, Archard JF (1971) Some microscopical investigations of grinding and abrasive wear. J Microsc-Oxford. https://doi.org/10.1111/j.1365-2818.1971.tb02357.x

  17. 17.

    Diniz AE et al (2014) Tecnologia da Usinagem dos Materiais. Artliber, São Paulo

    Google Scholar 

  18. 18.

    Trent EM, Wright PK (2000) Metal cutting. Butterworth-Heinemann, Woburn

    Google Scholar 

  19. 19.

    Villares Metals (2013) Ligas intermediárias de Níquel. Villares Metals S.A. http://www.villaresmetals.com.br/villares/pt/Produtos/Acos-Valvula. Accessed 05 March 2019

Download references

Acknowledgments

The authors acknowledge the Coordination of Superior Level Staff Improvement (Capes) for providing the scholarship, Villares Metals for providing the valve steels for the cutting tests, and Sandvik Coromant for providing the cutting tools.

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Correspondence to Armando Ítalo Sette Antonialli.

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Carvalho, M.R.D.D., Antonialli, A.Í.S. & Diniz, A.E. A machinability evaluation based on the thermal and mechanical properties of two engine valve steels. Int J Adv Manuf Technol 110, 3209–3219 (2020). https://doi.org/10.1007/s00170-020-06108-w

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Keywords

  • Turning
  • Cutting speed
  • Cutting tool geometry
  • High-pressure coolant