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Journal of Materials Science

, Volume 44, Issue 1, pp 257–265 | Cite as

Effectiveness of Ni-based diffusion barriers in preventing hard zone formation in ferritic steel joints

  • R. Anand
  • C. Sudha
  • T. Karthikeyan
  • A. L. E. Terrance
  • S. SarojaEmail author
  • M. Vijayalakshmi
Article

Abstract

A numerical procedure based on finite difference method was used to simulate the formation of ‘hard’ and ‘soft’ zones, in dissimilar weldments of 9Cr–1Mo and 2¼Cr–1Mo steels during high temperature exposure. Kinetic analysis of the calculated diffusion profiles showed that the activation energy for carbon diffusion in Cr–Mo steels is marginally higher than that in Fe–C system. Calculations were extended to incorporate the effect of Ni-based interlayers between 2¼Cr–1Mo and 9Cr–1Mo ferritic steels. The presence of a diffusion barrier was found to reduce the propensity for formation of hard and soft zones, which is related to the interaction parameter \( \varepsilon_{\rm C}^{\rm M}. \) Thickness of the interlayer required to suppress the formation of hard zone was optimized by the calculations. Transition joints of ferritic steels with Inconel 182 as the interlayer of thickness close to that predicted by the computations were fabricated and exposed to elevated temperature. Microstructural studies and hardness measurements further confirmed the effectiveness of Ni-based interlayers in preventing hard zone formation.

Keywords

PWHT Ferritic Steel Diffusion Profile Weld Interface Soft Zone 

Notes

Acknowledgements

The authors thank Dr. Baldev Raj, Director, IGCAR, and Dr. P. R. Vasudeva Rao, Director, Metallurgy and Materials Group, for their support and encouragement for this project. The authors also thank Dr. S. K. Albert and Dr. K. Laha, Scientific Officers, MMG, IGCAR, for their help and useful suggestions.

References

  1. 1.
    Kim BC, Ann HS, Song JT (1992) In: Proceedings of the international trends in welding science and technology. ASM International, Materials Park, Ohio, pp 307–312Google Scholar
  2. 2.
    Albert SK, Gill TPS, Tyagi AK, Mannan SL, Kulkarni SD, Rodriguez P (1997) Weld J 76:135Google Scholar
  3. 3.
    Lundin CD, Khan KK, Yang D (1996) Report No. 1 WRC Bull 407:1Google Scholar
  4. 4.
    Lundin CD, Khan KK, Yang D (1990) In: Proceedings of the recent trends in welding science and technology. ASM International, Materials Park, Ohio, pp 291–297Google Scholar
  5. 5.
    Goldstein JI, Moren AE (1978) Metall Trans 9A:1515CrossRefGoogle Scholar
  6. 6.
    Farkas D, Ohla K (1983) Oxid Met 19:99CrossRefGoogle Scholar
  7. 7.
    Bongartz K, Lupton DF, Schuster H (1980) Metall Trans 11A:1883CrossRefGoogle Scholar
  8. 8.
    Morral JE, Dupen BM, Law CC (1992) Metall Trans 23A:2069CrossRefGoogle Scholar
  9. 9.
    Buchmayr B (1990) Fundamentals and applications of ternary diffusion. Pergamon Press, New York, pp 227–240Google Scholar
  10. 10.
    Kirkaldy JS (1971) Oxidation of metals and alloys. ASM, Ohio, pp 101–114Google Scholar
  11. 11.
    Engström A, Höglund L, Ågren J (1994) Metall Trans 25A:1127CrossRefGoogle Scholar
  12. 12.
    Kozeschnik E, Pölt P, Brett S, Buchmayr B (2002) Sci Technol Weld Join 7:63CrossRefGoogle Scholar
  13. 13.
    Kozeschnik E, Warbichler P, Letofsky-Papst I, Brett S, Buchmayr B (2002) Sci Technol Weld Join 7:69CrossRefGoogle Scholar
  14. 14.
    Kucera J, Vrestal J, Stránskỳ K (1989) Defect Diffus Forum 66–69:1395Google Scholar
  15. 15.
    Gauzzi F, Missori S (1988) J Mater Sci 23:782. doi: https://doi.org/10.1007/BF01153967 CrossRefGoogle Scholar
  16. 16.
    Sudha C, Terrance ALE, Albert SK, Vijayalakshmi M (2002) J Nucl Mater 302:193CrossRefGoogle Scholar
  17. 17.
    Sudha C, Terrance ALE, Vijayalakshmi M (2002) In: Proceedings of the IIW Asian pacific international congress, Singapore. Welding Institute of Australia, pp 1–15Google Scholar
  18. 18.
    Sudha C, Thomas Paul V, Terrance ALE, Saroja S, Vijayalakshmi M (2006) Weld J 85:71Google Scholar
  19. 19.
    Huang ML, Wang L (1998) Metall Trans 29A:3037CrossRefGoogle Scholar
  20. 20.
    Pavlovsky J, Million B, Ciha K, Stránskỳ K (1991) Mater Sci Eng A 149:105CrossRefGoogle Scholar
  21. 21.
    Londolt B (1990) Diffusion in solids, metals and alloys. Springer-Verlag, Berlin, pp 372–435Google Scholar
  22. 22.
    Wada H (1985) Metall Trans 16A:1479CrossRefGoogle Scholar
  23. 23.
    Lupis CHP (1983) Chemical thermodynamics. Oxford University Press, North Holland, pp 491–501Google Scholar
  24. 24.
    Crank J (1956) The mathematics of diffusion. Oxford University Press, Oxford, pp 150–186Google Scholar
  25. 25.
    Birchenall CE, Mehl RF (1947) Trans AIME 171:143Google Scholar
  26. 26.
    Kucera J, Stránskỳ K (1982) Mater Sci Eng 52:1CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • R. Anand
    • 1
  • C. Sudha
    • 1
  • T. Karthikeyan
    • 1
  • A. L. E. Terrance
    • 1
  • S. Saroja
    • 1
    Email author
  • M. Vijayalakshmi
    • 1
  1. 1.Physical Metallurgy DivisionMetallurgy and Materials Group, Indira Gandhi Centre for Atomic ResearchKalpakkamIndia

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