Basic research on mechanism of BN inclusion in improving the machinability of steel

Authors

  • Chen Ya-nan State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing
  • Bao Yan-ping State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing
  • Wang Min National Engineering Research Center of Flat Rolling Equipment, University of Science and Technology Beijing
  • Cai Xiao-feng State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing
  • Wang Lin-jinga State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing
  • Zhao Li-hua State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing

DOI:

https://doi.org/10.3989/revmetalm.028

Keywords:

Boron Nitride (BN), Cutting mechanism, Free cutting steel, Inclusion, Machinability

Abstract


Boron nitride-added eco-friendly free cutting steel has recently drawn more and more attention. But, the mechanisms explaining the role of BN inclusions improving the machinability of steels is not very clear. In this investigation, the material removal mechanism for cutting of BN inclusions in steels is explored, using a combination of theoretical analysis and a series of experiments. First, the actual shape of BN inclusions is observed and the amount and distribution of BN inclusions is quantitatively analyzed. Subsequently, the cutting performance of the steel is determined by cutting experimental tests. Moreover, the micro mechanical properties and the material removal mechanisms for cutting of BN inclusions are investigated by means of nanoindentation. The results revealed that the BN inclusions are hexagonal and are uniformly distributed, their average content is 23.2 per unit area and their volume fraction is 0.51% in the steel with 74 ppm B and 180 ppm N. It is shown that BN inclusions can improve the cutting performance of steel significantly, and a model describing the material removal mechanism for cutting of BN inclusions is proposed. BN inclusions act as stress concentration source, lubrication and wrappage of hard particles.

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References

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Published

2014-12-30

How to Cite

Ya-nan, C., Yan-ping, B., Min, W., Xiao-feng, C., Lin-jinga, W., & Li-hua, Z. (2014). Basic research on mechanism of BN inclusion in improving the machinability of steel. Revista De Metalurgia, 50(4), e028. https://doi.org/10.3989/revmetalm.028

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Articles