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Metallurgical and Materials Transactions B

, Volume 47, Issue 6, pp 3245–3256 | Cite as

Post-weld Tempered Microstructure and Mechanical Properties of Hybrid Laser-Arc Welded Cast Martensitic Stainless Steel CA6NM

  • Fatemeh Mirakhorli
  • Xinjin Cao
  • Xuan-Tan Pham
  • Priti Wanjara
  • Jean-Luc Fihey
Article

Abstract

Manufacturing of hydroelectric turbine components involves the assembly of thick-walled stainless steels using conventional multi-pass arc welding processes. By contrast, hybrid laser-arc welding may be an attractive process for assembly of such materials to realize deeper penetration depths, higher production rates, narrower fusion, and heat-affected zones, and lower distortion. In the present work, single-pass hybrid laser-arc welding of 10-mm thick CA6NM, a low carbon martensitic stainless steel, was carried out in the butt joint configuration using a continuous wave fiber laser at its maximum power of 5.2 kW over welding speeds ranging from 0.75 to 1.2 m/minute. The microstructures across the weldment were characterized after post-weld tempering at 873 K (600 °C) for 1 hour. From microscopic examinations, the fusion zone was observed to mainly consist of tempered lath martensite and some residual delta-ferrite. The mechanical properties were evaluated in the post-weld tempered condition and correlated to the microstructures and defects. The ultimate tensile strength and Charpy impact energy values of the fully penetrated welds in the tempered condition were acceptable according to ASTM, ASME, and industrial specifications, which bodes well for the introduction of hybrid laser-arc welding technology for the manufacturing of next generation hydroelectric turbine components.

Keywords

Welding Austenite Martensite Welding Speed Charpy Impact 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Nomenclature

Ac1

Temperature at which austenite begins to form during heating

BM

Base metal

EBW

Electron beam welding

FCAW

Flux core arc welding

FZ

Fusion zone

GMAW

Gas metal arc welding

GTAW

Gas tungsten arc welding

HAZ

Heat-affected zone

HLAW

Hybrid laser-arc welding

Mf

Martensite finish temperature

Ms

Martensite start temperature

OM

Optical microscopy

PMZ

Partially melted zone

PWHT

Post-weld heat treatment

SEM

Scanning electron microscopy

Notes

Acknowledgments

The authors are grateful to Alstom, Hydro-Québec, Aero 21 Program of the National Research Council of Canada and National Science and Engineering Research Council of Canada (NSERC) for the financial supports. The authors also wish to thank E. Poirier and X. Pelletier of NRC Aerospace for their technical assistance during welding and metallographic preparation.

References

  1. 1.
    P. Bilmes, M. Solari., and C. Llorente: Mater. Charact., 2001, vol. 46(4), pp. 285–96.CrossRefGoogle Scholar
  2. 2.
    A. Mahrle and E. Beyer: J Laser Appl, 2006, vol. 18, pp. 169–80.CrossRefGoogle Scholar
  3. 3.
    F. Mirakhorli, X. Cao, X.T. Pham, P. Wanjara, and J.-L. Fihey: MS&T 2014 Conference, Pittsburgh, PA, 2014, pp. 1891–900.Google Scholar
  4. 4.
    E. Folkhard, G. Rabensteiner and E. Perteneder: Welding metallurgy of stainless steels. Springer, Vienna, 1988, pp. 9–125.CrossRefGoogle Scholar
  5. 5.
    D. Thibault, P. Bocher, and M. Thomas: J. Mater. Process. Technol., 2009, vol. 209, pp. 2195-202.CrossRefGoogle Scholar
  6. 6.
    D. Carrouge, H. Bhadeshia and P. Woollin: Sci. Technol. Weld. Join., 2004, vol. 9, pp. 377–89.CrossRefGoogle Scholar
  7. 7.
    S. Sarafan, P. Wanjara, H. Champliaud, and D. Thibault: Int. J. Adv. Manuf. Technol., 2015, vol. 78, pp. 1–13.CrossRefGoogle Scholar
  8. 8.
    S. Morito, X. Huang, T. Furuhara, T. Maki, and N. Hansen: Acta Mater., 2006, vol. 54(19), pp. 5323–31.CrossRefGoogle Scholar
  9. 9.
    V. Vander, and F. George., Metallography, Principles and Practice, New York: ASM International, 1984, pp. 170-180.Google Scholar
  10. 10.
    Y. Song, X. Li, L. Rong, D. Ping, F. Yin, Y. Li: Mater. Lett., 2010, vol. 64(13), pp. 1411-14.CrossRefGoogle Scholar
  11. 11.
    E.B.A. Akhiate, D. Thibault, and M. Brochu: COM 2014, Vancouver, BC, Canada, 2014.Google Scholar
  12. 12.
    M. Santella, R. Swindeman, R. Reed, and J. Tanzosh: EPRI Conference on 9Cr Materials Fabrication and Joining Technologies, 2001.Google Scholar
  13. 13.
    Y. Song, X. Li, L. Rong, Y. Li: Mater. Sci. Eng., A., 2011, vol. 528, pp. 4075-79.CrossRefGoogle Scholar
  14. 14.
    Y. Song, D. Ping, F. Yin, X. Li, Y. Li: Mater. Sci. Eng. A., 2010, vol. 527, pp. 614-18.CrossRefGoogle Scholar
  15. 15.
    G. Krauss: Phase Transformations in Steels, Woodhead Publishing, 2012, vol. 2, pp. 126–50.Google Scholar
  16. 16.
    D.A. Porter and K.E. Easterling: Phase Transformations in Metals and Alloys, (Revised Reprint), CRC Press, 1992, pp. 385–415.Google Scholar
  17. 17.
    R. Caron, G. Krauss: Metall. Trans., 1972, vol. 3, pp. 2381-89.CrossRefGoogle Scholar
  18. 18.
    S. Kimmins, D. Gooch: Metal science, 1983, vol. 17, pp. 519-32.CrossRefGoogle Scholar
  19. 19.
    M. De Sanctis, R. Valentini, G. Lovicu, A. Dimatteo, R. Ishak, U. Migliaccio, R. Montanari, and E. Pietrangeli: Mater. Sci. Forum., 2013, vol 762, pp. 176-82.CrossRefGoogle Scholar
  20. 20.
    B. Qin, Z. Wang, Q. Sun: Mater. Charact., 2008, vol. 59, pp. 1096–100.CrossRefGoogle Scholar
  21. 21.
    S. Zappa, H. Svoboda, N.R. De Rissone, E. Surian, and L. De Vedia: Weld. J., 2012, vol. 91(3), pp. 83.Google Scholar
  22. 22.
    M. AlDawood, I. ElMahallawi, M. AbdElAzim, M. ElKoussy: J. Mater. Sci. Technol., 2004, vol. 20, pp. 363-69.CrossRefGoogle Scholar
  23. 23.
    A. Candelaria, C. Pinedo: J. Mater. Sci. Lett., 2003, vol. 22, pp. 1151-53.CrossRefGoogle Scholar
  24. 24.
    J.C. Lippold and D.J. Kotecki: Welding metallurgy and weldability of stainless steels, Wiley-VCH, Hoboken, 2005, pp. 59-86.Google Scholar
  25. 25.
    A. Trudel, M. Sabourin and M. Brochu: Int. J. Fatigue, 2014, vol. 66, pp. 39-46.CrossRefGoogle Scholar
  26. 26.
    T. Hanamura, S. Torizuka, S. Tamura, S. Enokida, H. Takechi: ISIJ international, 2013, vol. 53, pp. 2218-25.CrossRefGoogle Scholar
  27. 27.
    G. Avramovic-Cingara, C.A. Saleh, M. Jain and D. Wilkinson: Metall. Mater. Trans. A, 2009, vol. 40A, pp. 3117-27.CrossRefGoogle Scholar
  28. 28.
    J. Kadkhodapour, A. Butz, S. Ziaei-Rad, S. Schmauder: Int. J. Plast., 2011, vol. 27, pp. 1103-25.CrossRefGoogle Scholar
  29. 29.
    D.L. Steinbrunner, D. Matlock, G. Krauss: Metall. Trans. A, 1988, vol. 19A, pp. 579-89.CrossRefGoogle Scholar
  30. 30.
    H.S. Lee, B. Hwang, S. Lee, C.G. Lee, S.-J. Kim: Metall. Mater. Trans. A, 2004, vol. 35A, pp. 2371-82.CrossRefGoogle Scholar
  31. 31.
    Y. Iwabuchi: JSME International Journal, 2003, vol. A46, pp. 441-46.CrossRefGoogle Scholar
  32. 32.
    P. Wang, S. Lu, N. Xiao, D. Li, Y. Li: Mater. Sci. Eng. A, 2010, vol. 527, pp. 3210-16.CrossRefGoogle Scholar
  33. 33.
    G.E. Dieter and D. Bacon: Mechanical metallurgy, McGraw-Hill, New York, 1986, pp. 471-500.Google Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2016

Authors and Affiliations

  • Fatemeh Mirakhorli
    • 1
    • 2
  • Xinjin Cao
    • 1
    • 2
  • Xuan-Tan Pham
    • 1
  • Priti Wanjara
    • 2
  • Jean-Luc Fihey
    • 1
  1. 1.Mechanical Engineering DepartmentÉcole de technologie supérieureMontrealCanada
  2. 2.National Research Council Canada–AerospaceMontrealCanada

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