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Influence of shielding gases on grain refinement in welds of stabilized 21 % Cr ferritic stainless steel


The influence of shielding gas mixtures of argon, nitrogen, and oxygen was experimentally investigated in order to evaluate the possibilities of grain refinement in autogenous welds of stabilized 21 % Cr ferritic stainless steel heats that would otherwise solidify in a columnar fashion. The main focus was on metallography and weld metal compositions, but some mechanical and corrosion properties were also evaluated. According to the findings, substantial grain refinement can be achieved by using nitrogen plus oxygen additions to the argon shielding gas in gas tungsten arc welding. Nitrogen addition alone was insufficient because oxygen was needed to produce oxide inoculants for nitrides and a uniform slag to protect the solidifying weld pool surface from nitrogen outgassing. Excessive nitride precipitation in ferrite deteriorated some of the properties, but an interesting finding in some of the welds was the presence of retained austenite instead of martensite. However, laser welding experiments did not bring about similar features in the weld metals. Apparently, nitrogen absorption is too modest to have an effect in disk laser welding even when using a non-keyhole welding mode.

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  1. 1.

    Yazawa Y, Ishii K, Ishii T, Okada S, Ujiro T, Yamashita H (2007) JFE443CT, Ni, Mo-free stainless steel with high corrosion resistance. Corros Eng 56:599–606

    Google Scholar 

  2. 2.

    Charles J, Mithieux JD, Santacreu PO, Peguet L (2008) The ferritic stainless steel family: the appropriate answer to nickel volatility? 6th European Stainless Steel Conference H02-1:703–719

  3. 3.

    Appolloni L, Rocchi C, Guerra R, Sciaboletta D, Ruffini F (2011) New grades of stabilized superferritic stainless steel: Main properties and applications. 7th European Stainless Steel Conference

  4. 4.

    Villafuerte JC, Kerr HW, David SA (1995) Mechanisms of equiaxed grain formation in ferritic stainless steel gas tungsten arc welds. Mater Sci Eng A 194:187–191

    Article  Google Scholar 

  5. 5.

    Kimura K, Takahashi A (2010) Development of NSSC® PDX—a ferritic stainless steel with excellent formability. Nippon Steel Tech Rep 99:51–55

    Google Scholar 

  6. 6.

    Davies GJ, Garland JG (1975) Solidification structures and properties of fusion welds. Int Metall Rev 20:100–103

    Google Scholar 

  7. 7.

    Krysiak KF (1986) Welding behaviour of ferritic stainless steels—an overview. Weld J 65:37–41

    Google Scholar 

  8. 8.

    Inui K, Noda T, Shimizu T, Nagata M (2003) Development of the ferritic stainless steel welding wire providing fine grain microstructure weld metal for the components of automotive exhaust system. SAE Technical Paper Series 2003-01-0979

  9. 9.

    Inui K, Minamikawa H, Noda T (2006) Welding wire and welding method using the wire. U.S. patent US 7,026,576 B2 11.04.2006

  10. 10.

    Saito T, Ito T, Agata Y, Nonaka S, Kobayashi M (2006) Ferritic stainless steel welding wire and manufacturing method thereof. Canadian patent CA 2,533,946 A1 26.07.2006

  11. 11.

    Villaret V, Deschaux-Beaume F, Bordreuil C, Rouquette S, Chovet C (2013) Influence of filler wire composition on weld microstructures of a 444 ferritic stainless steel grade. J Mater Process Technol 213:1538–1547

    Article  Google Scholar 

  12. 12.

    Espy RH (1982) Weldability of nitrogen-strengthened stainless steels. Weld J 61:149s–156s

    Google Scholar 

  13. 13.

    Nelson TW, Lippold JC, Mills MJ (1999) Nature and evolution of the fusion boundary in ferritic-austenitic dissimilar weld metals, part 1—nucleation and growth. Weld J 78:329s–337s

    Google Scholar 

  14. 14.

    Castro R, de Cadenet JJ (1975) Welding metallurgy of stainless and heat-resisting steels. Cambridge University Press, Cambridge, pp 12–13

    Google Scholar 

  15. 15.

    Kou S, Le Y (1982) The effect of quenching on the solidification structure and transformation behavior of stainless steel welds. Metall Mater Trans A 13:1141–1152

    Article  Google Scholar 

  16. 16.

    Kou S (2003) Welding metallurgy. Wiley, Hoboken, pp 283–284

    Google Scholar 

  17. 17.

    Plumtree A, Gullberg R (1980) Influence of interstitial and some substitutional alloying elements. Lula RA (eds). Toughness of ferritic stainless steels. ASTM, 34–55

  18. 18.

    Hooijmans JW, Den Ouden G (1992) The influence of oxygen on nitrogen absorption during arc melting of iron. Weld J 71:377s–380s

    Google Scholar 

  19. 19.

    du Toit M, Pistorius PC (2007) The influence of oxygen on the nitrogen content of autogenous stainless steel arc welds. Weld J 86:222s–230s

    Google Scholar 

  20. 20.

    Dong W, Kokawa H, Sato YS, Tsukamoto S (2003) Nitrogen absorption by iron and stainless steels during CO2 laser welding. Metall Mater Trans B 34:75–82

    Article  Google Scholar 

  21. 21.

    Greeff ML, du Toit M (2006) Looking at the sensitization of 11–12% chromium EN 1.4003 stainless steels during welding. Weld J 85:243s–251s

    Google Scholar 

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The current work has been carried out within a project entitled NGF of the Demanding Applications program of FIMECC Ltd. The authors are grateful to the Finnish Funding Agency for Technology and Innovation (Tekes) and Outokumpu Oyj for financial support. S.A. is also grateful to the Technology Industries of Finland Centennial Foundation Fund for the Association of Finnish Steel and Metal Producers and for the support from Outokumpu Stainless Oy, Tornio Research Centre.

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Correspondence to S. Anttila.

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Doc. IIW-2475, recommended for publication by Commission IX “Behaviour of Metals Subjected to Welding”.

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Anttila, S., Porter, D.A. Influence of shielding gases on grain refinement in welds of stabilized 21 % Cr ferritic stainless steel. Weld World 58, 805–817 (2014).

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  • Ferritic stainless steels
  • Metallography
  • Weld metal