Skip to main content
Log in

Laser transformation hardening of tempered 4340 steel

  • Published:
Metallurgical Transactions A Aims and scope Submit manuscript

Abstract

A CO2 laser with a fixed laser power of 1.8 KW was employed to harden the surface of some AISI 4340 steel specimens, with a scan rate from 5 to 10 mm/s. The influence of scan rates and tempering treatments of the alloy on the hardness profile and microstructure of the laserhardened zone was analyzed. Microstructures in the hardened zone consisted of mainly lath and twinned martensites. However, depending on the scan rate, autotempered martensite has also been found. In the transition zone of laser-treated specimens, partially dissolved carbides with austenite envelopes and/or austenite islands in a matrix of martensite were observed. The time required for complete carbide dissolution into austenite during laser treatment depended on the tempering conditions. A lower tempering temperature of the alloy produced a deeper hardened zone and a narrower transition zone in the hardness profile. A simple mathematical estimation of the hardness profile, based on the carbon diffusion distance in austenite, was performed. The calculated results are in reasonably good agreement with the measured hardness profiles and the microstructural observations in the laser transformation hardening process.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. J. Mazumder:J. Met., 1983, vol. 35 (5), pp. 18–26.

    Google Scholar 

  2. H.B. Singh, S.M. Copley, and M. Bass:Metall. Trans. A, 1981, vol. 12A, pp. 138–40.

    Google Scholar 

  3. A.N. Safonov, V.M. Tarasenko, A.F. Baskov, A.A. Nikitin, I.V. Lyasotskii, and E.V. Safonov:Metalloved. Term. Obrab. Met., 1985, no. 4, pp. 5-9.

  4. C. Chen:Chin. J. Mater. Sci., 1986, vol. 18A (2), pp. 70–77.

    CAS  Google Scholar 

  5. G. Molinder:Acta Metall., 1956, vol. 4, pp. 565–71.

    Article  CAS  Google Scholar 

  6. R.R. Judd and H.W. Paxton:Trans. AIME, 1968, vol. 242, pp. 206–13.

    CAS  Google Scholar 

  7. G.R. Speich and A. Szirmae:Trans. AIME, 1969, vol. 245, pp. 1063–73.

    CAS  Google Scholar 

  8. G.R. Speich, V.A. Demarest, and R.L. Miller:Metall. Trans. A, 1981, vol. 12A, pp. 1419–28.

    Google Scholar 

  9. M.F. Ashby and K.E. Easterling:Acta Metall., 1984, vol. 32, pp. 1935–48.

    Article  CAS  Google Scholar 

  10. H.J. Hegge and J.Th.M. De Hosson:Scripta Metall., 1987, vol. 21, pp. 1737–42.

    Article  CAS  Google Scholar 

  11. R.A. Grange:Trans. AIME, 1966, vol. 59, pp. 26–48.

    CAS  Google Scholar 

  12. A. Solina, M.D. Sanctis, L. Paganini, A. Blarasin, and S. Quaranta:J. Heat Treat., 1984, vol. 3 (3), pp. 193–204.

    CAS  Google Scholar 

  13. F.F. Vaughn, V.R. Farlow, and E.R. Meyer:Trans. ASM, 1942, vol. 30, pp. 516–40.

    CAS  Google Scholar 

  14. S. Kou, D.K. Sun, and Y.P. Le:Metall. Trans. A, 1983, vol. 14A, pp. 643–53.

    Google Scholar 

  15. O.A. Sandven:Int. Laser Processing Conf., Anaheim, CA, Nov. 16–17, 1981, pp. 1-19.

  16. J.R. Bradley and S. Kim:Metall. Trans. A, 1988, vol. 19A, pp. 2013–25.

    CAS  Google Scholar 

  17. J.R. Bradley and D. Kim:Scripta Metall., 1989, vol. 23, pp. 131–36.

    Article  CAS  Google Scholar 

  18. G. Krauss and A.R. Marder:Metall. Trans., 1971, vol. 2, pp. 2343–57.

    CAS  Google Scholar 

  19. Gareth Thomas:Metall. Trans., 1971, vol. 2, pp. 2373–85.

    Article  CAS  Google Scholar 

  20. J. Nutting:J. Iron Steel Inst., 1969, vol. 6, pp. 872–93.

    Google Scholar 

  21. M. Melander and J. Nicolov:J. Heat Treat., 1985, vol. 4 (1), pp. 32–38.

    CAS  Google Scholar 

  22. Earl R. Parker:Metall. Trans. A, 1977, vol. 8A, pp. 1025–42.

    CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Additional information

Formerly Graduate Research Assistant, Institute of Materials Science and Engineering, National Taiwan University

Rights and permissions

Reprints and permissions

About this article

Cite this article

Shiue, R.K., Chen, C. Laser transformation hardening of tempered 4340 steel. Metall Trans A 23, 163–170 (1992). https://doi.org/10.1007/BF02660862

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02660862

Keywords

Navigation