Journal of Materials Science

, Volume 51, Issue 10, pp 4864–4879 | Cite as

Metallurgical characterization of coupled carbon diffusion and precipitation in dissimilar steel welds

  • Fanny Mas
  • Catherine Tassin
  • Nathalie Valle
  • Florence Robaut
  • Frédéric Charlot
  • Miguel Yescas
  • François Roch
  • Patrick Todeschini
  • Yves Bréchet
Original Paper

Abstract

The complex microstructures developed during post-welding heat-treatment in the vicinity of the fusion line between a ferritic and austenitic steel were examined in the case of submerged arc welded 18MND5/309L dissimilar joints. Quantitative measurements of the carbon distribution in the as-welded and post-weld heat-treated conditions were performed by both wavelength dispersive spectrometry and secondary ion mass spectrometry. The extent of carbon diffusion was confirmed by hardness profiles performed by nanoindentation. On the low-alloy ferritic side, decarburization resulted in cementite dissolution allowing the evolution of the bainitic structure toward a large-grained ferritic region. In the weld metal, the carbon content reached unusually high levels and an intense precipitation of chromium-rich carbides was observed in both the interfacial martensitic layer and the austenitic weld metal. The evolution of the precipitation as a function of the distance from the interface was analyzed in terms of crystallography, chemistry, volume fractions, and size distributions. Automated crystal orientation mapping in a transmission electron microscope allowed identification of the precipitates extracted on carbon replicas from both the martensitic and austenitic matrices. A 3D reconstruction of the carbides population in the martensitic layer was performed by serial cutting with a focused ion beam: M7C3 and M23C6 were found to coexist in the two carburized regions, but displayed different sizes, compositions, and morphologies, depending on their location with respect to the fusion line. This evolution in terms of precipitation was analyzed taking into account the local microstructure and composition.

References

  1. 1.
    Sopoušek J, Foret R, Jan V (2004) Simulation of dissimilar weld joints of steel P91. Sci Technol Weld Join 9(1):59–64CrossRefGoogle Scholar
  2. 2.
    Race JM, Bhadeshia H (1993) Carbon migration across dissimilar steel welds. Int Trends Weld Sci Technol 1–5Google Scholar
  3. 3.
    Gómez X, Echeberría J (2000) Microstructure and mechanical properties of low alloy steel T11–austenitic stainless steel 347H bimetallic tubes. Mater Sci Technol 16(2):187–193CrossRefGoogle Scholar
  4. 4.
    Silva CC, Miranda HC, de Sant’Ana HB, Farias JP (2013) Austenitic and ferritic stainless steel dissimilar weld metal evaluation for the applications as-coating in the petroleum processing equipment. Mater Des 47:1–8CrossRefGoogle Scholar
  5. 5.
    Foret R, Zlamal B, Sopousek J (2006) Structural stability of dissimilar weld between two Cr-Mo-V steels. Weld J 85:211s–217sGoogle Scholar
  6. 6.
    Darken LS (1949) Diffusion of carbon in austenite with a discontinuity in composition. Trans AIME 180(430–438):53Google Scholar
  7. 7.
    Christoffel RJ, Curran RM (1956) Carbon migration in welded joints at elevated temperatures. Weld J 35:457s–465sGoogle Scholar
  8. 8.
    Race JM, Bhadeshia HKDH (1992) Precipitation sequences during carburisation of Cr–Mo steel. Mater Sci Technol 8(10):875–882CrossRefGoogle Scholar
  9. 9.
    Kozeschnik E, Pölt P, Brett S, Buchmayr B (2002) Dissimilar 2·25Cr/9Cr and 2Cr/0·5CrMoV steel welds: part 1: characterisation of weld zone and numerical simulation. Sci Technol Weld Join 7(2):63–68CrossRefGoogle Scholar
  10. 10.
    Huang ML, Wang DL (1998) Carbon migration in 5Cr-0.5 Mo/21Cr-12Ni dissimilar metal welds. Metall Mater Trans A 29(12):3037–3046CrossRefGoogle Scholar
  11. 11.
    Albert SK, Gill TPS, Tyagi AK, Mannan SL, Kulkarni SD, Rodriguez P (1997) Soft zone formation in dissimilar welds between two Cr-Mo steels. Weld J Weld Res Suppl 76(3):135–142Google Scholar
  12. 12.
    Kozeschnik E, Warbichler P, Letofsky-Papst I, Brett S, Buchmayr B (2002) Dissimilar 2·25Cr/9Cr and 2Cr/0·5CrMoV steel welds: part 2: identification of precipitates. Sci Technol Weld Join 7(2):69–76CrossRefGoogle Scholar
  13. 13.
    Lundin CD (1982) Dissimilar metal welds-transition joints literature review. Weld J 61(2):58–63Google Scholar
  14. 14.
    Gauzzi F, Missori S (1988) Microstructural transformations in austenitic-ferritic transition joints. J Mater Sci 23(3):782–789. doi:10.1007/BF01153967 CrossRefGoogle Scholar
  15. 15.
    He K, Brown A, Brydson R, Edmonds DV (2006) Analytical electron microscope study of the dissolution of the Fe3C iron carbide phase (cementite) during a graphitisation anneal of carbon steel. J Mater Sci 41(16):5235–5241. doi:10.1007/s10853-006-0588-4 CrossRefGoogle Scholar
  16. 16.
    Scott CP, Drillet J (2007) A study of the carbon distribution in retained austenite. Scr Mater 56(6):489–492CrossRefGoogle Scholar
  17. 17.
    Valle N, Drillet J, Bouaziz O, Migeon H-N (2006) Study of the carbon distribution in multi-phase steels using the NanoSIMS 50. Appl Surf Sci 252(19):7051–7053CrossRefGoogle Scholar
  18. 18.
    Laigo J, Christien F, Le Gall R, Tancret F, Furtado J (2008) SEM, EDS, EPMA-WDS and EBSD characterization of carbides in HP type heat resistant alloys. Mater Charact 59(11):1580–1586CrossRefGoogle Scholar
  19. 19.
    Lan L, Qiu C, Zhao D, Gao X, Du L (2012) Analysis of martensite–austenite constituent and its effect on toughness in submerged arc welded joint of low carbon bainitic steel. J Mater Sci 47(11):4732–4742. doi:10.1007/s10853-012-6346-x CrossRefGoogle Scholar
  20. 20.
    Li YJ, Choi P, Borchers C, Chen YZ, Goto S, Raabe D, Kirchheim R (2011) Atom probe tomography characterization of heavily cold drawn pearlitic steel wire. Ultramicroscopy 111(6):628–632CrossRefGoogle Scholar
  21. 21.
    Garcia-Mateo C, Caballero FG, Miller MK, Jimenez JA (2011) On measurement of carbon content in retained austenite in a nanostructured bainitic steel. J Mater Sci 47(2):1004–1010. doi:10.1007/s10853-011-5880-2 CrossRefGoogle Scholar
  22. 22.
    Seidel F, Stock H-R, Mayr P (1997) Glow discharge optical spectroscopy depth profiles of ion implanted steel, titanium and titanium nitride coatings. Thin Solid Films 308:425–429CrossRefGoogle Scholar
  23. 23.
    Mändl S, Fritzsche B, Manova D, Hirsch D, Neumann H, Richter E, Rauschenbach B (2005) Wear reduction in AISI 630 martensitic stainless steel after energetic nitrogen ion implantation. Surf Coat Technol 195(2):258–263CrossRefGoogle Scholar
  24. 24.
    Helander T, Ågren J (1997) Computer simulation of multicomponent diffusion in joints of dissimilar steels. Metall Mater Trans A 28(2):303–308CrossRefGoogle Scholar
  25. 25.
    Larsson H, Engström A (2006) A homogenization approach to diffusion simulations applied to α + γ Fe–Cr–Ni diffusion couples. Acta Mater 54(9):2431–2439CrossRefGoogle Scholar
  26. 26.
    Pan C, Wang R, Gui J, Shi Y (1990) Direct TEM observation of microstructures of the austenitic/carbon steels welded joint. J Mater Sci 25(7):3281–3285. doi:10.1007/BF00587687 CrossRefGoogle Scholar
  27. 27.
    Ishida T (1991) Formation of stainless steel layer on mild steel by welding arc cladding. J Mater Sci 26(23):6431–6435. doi:10.1007/BF02387825 CrossRefGoogle Scholar
  28. 28.
    Nelson TW, Lippold JC, Mills MJ (2000) Nature and evolution of the fusion boundary in ferritic-austenitic dissimilar metal welds. Part 2-On-cooling transformations. Weld Res 79:267s–277sGoogle Scholar
  29. 29.
    Wu Y, Patchett BM (1992) Formation of crack-susceptible structures of weld overlay of corrosion resistant alloys. Mater Perform Sulphur Energy 283–295Google Scholar
  30. 30.
    Iso 16592 Analyse par microfaisceaux—analyse par microsonde électronique (microsonde de Castaing)—lignes directrices pour le dosage du carbone dans les aciers par la droite d’étalonnageGoogle Scholar
  31. 31.
    Oliver WC, Pharr GM (1992) An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J Mater Res 7(6):1564–1583CrossRefGoogle Scholar
  32. 32.
    Gatan ion beam etching in Material Characterization, Final report Isolde Gräf, TU Darmstadt in cooperation with Gatan GmbH, MünichGoogle Scholar
  33. 33.
    Rauch EF, Duft A (2005) Orientation maps derived from TEM diffraction patterns collected with an external CCD camera. Mater Sci Forum 495–497:197–202CrossRefGoogle Scholar
  34. 34.
    Rauch EF, Véron M, Nicolopoulos S, Bultreys D (2012) Orientation and phase mapping in TEM microscopy (EBSD-TEM like): applications to materials science. Solid State Phenom 186:13–15CrossRefGoogle Scholar
  35. 35.
    Oliver WC, Pharr GM (2004) Measurement of hardness and elastic modulus by instrumented indentation: advances in understanding and refinements to methodology. J Mater Res 19(01):3–20CrossRefGoogle Scholar
  36. 36.
    Moeck P, Rouvimov S, Rauch EF, Veron M, Kirmse H, Häusler I, Neumann W, Bultreys D, Maniette Y, Nicolopoulos S (2011) High spatial resolution semi-automatic crystallite orientation and phase mapping of nanocrystals in transmission electron microscopes. Cryst Res Technol 46(6):589–606CrossRefGoogle Scholar
  37. 37.
    Shtansky DV, Nakai K, Ohmori Y (2000) Decomposition of martensite by discontinuous-like precipitation reaction in an Fe–17Cr–0.5C alloy. Acta Mater 48(4):969–983CrossRefGoogle Scholar
  38. 38.
    Berkane R, Gachon JC, Charles J, Hertz J (1987) A thermodynamic study of the chromium-carbon system. CALPHAD 11(4):375–382CrossRefGoogle Scholar
  39. 39.
    Shtansky DV, Nakai K, Ohmori Y (1999) Crystallography and interface boundary structure of pearlite with M 7 C 3 carbide lamellae. Acta Mater 47(4):1105–1115CrossRefGoogle Scholar
  40. 40.
    Kozeschnik E, Buchmayr B (1999) MATCALC—a simulation tool for multicomponent thermodynamics, diffusion and phase transformations. In Fifth international seminar on the numerical analysis of weldability. pp. 349–361Google Scholar
  41. 41.
  42. 42.
    Van Landeghem HP, Gouné M, Redjaïmia A (2012) Nitride precipitation in compositionally heterogeneous alloys: nucleation, growth and coarsening during nitriding. J Cryst Growth 341(1):53–60CrossRefGoogle Scholar
  43. 43.
    Villars P, Cenzual K (2010) Pearson’s crystal data: crystal structure database for inorganic compounds. ASM International, Materials ParkGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Fanny Mas
    • 1
    • 2
  • Catherine Tassin
    • 1
    • 2
  • Nathalie Valle
    • 3
  • Florence Robaut
    • 4
  • Frédéric Charlot
    • 4
  • Miguel Yescas
    • 5
  • François Roch
    • 5
  • Patrick Todeschini
    • 6
  • Yves Bréchet
    • 1
    • 2
  1. 1.Université Grenoble Alpes, SIMAPGrenobleFrance
  2. 2.CNRS, SIMAPGrenobleFrance
  3. 3.Centre Public Gabriel LippmannBelvauxLuxembourg
  4. 4.Consortium des Moyens Technologiques CommunsGrenoble-INPSt. Martin d’HèresFrance
  5. 5.AREVA NPParis La DéfenseFrance
  6. 6.EDF R&DMoret-Sur-LoingFrance

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