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Effects of nitrogen and hydrogen in argon shielding gas on bead profile, delta-ferrite and nitrogen contents of the pulsed GTAW welds of AISI 316L stainless steel

Auswirkungen von Stickstoff und Wasserstoff im Argon-Schutzgas auf das Nahtprofil, den δ-Ferritanteil und den Stickstoffgehalt von gepulsten Wolfram-Inertgas-Schweißungen eines AISI 316L Stahls
Panyasak Phakpeetinan, Amnuysak Chianpairot, Ekkarut Viyanit, Fritz Hartung and Gobboon Lothongkum
From the journal Materials Testing
https://doi.org/10.3139/120.110892

Abstract

The general effects of 1, 2, 3 and 4 vol.-% nitrogen and 1, 5 and 10 vol.-% hydrogen in argon shielding gas on weld bead profile (depth/width ratio: D/W) and the δ-ferrite content of AISI 316L pulsed GTAW welds were investigated. The limits for imperfections for the quality levels of welds were based on ISO 5817 B. The plates with a thickness of 6 mm were welded at the flat position and the bead on plate. Increasing hydrogen content in argon shielding gas increases the D/W ratio. Excessive hydrogen addition to argon shielding gas will result in incompletely filled groove and excessive penetration of weld. Increasing welding speed decreases the weld-metal volume and the D/W ratios. Nitrogen addition to argon shielding gas has no effect on the D/W ratio. The addition of a mixture of nitrogen and hydrogen to argon shielding gas on the D/W ratio does not show any interaction between them. An effect on the D/W ratio can be exclusively observed as a function of hydrogen content. Increasing hydrogen content in argon shielding gas increases the δ-ferrite content of weld metal. Increasing either nitrogen content in shielding gas or welding speed decreases the δ-ferrite content of weld metal. The nitrogen addition increases the weld metal nitrogen content, however, the hydrogen addition leads to a decrease of weld metal nitrogen content.

Kurzfassung

Die allgemeinen Auswirkungen von 1, 2, 3 und 4 vol.-% Stickstoff sowie 1, 5 und 10 vol.-% Wasserstoff im Argon-Schutzgas auf das Nahtprofil (Tiefe-zu-Weite-Verhältnis: D/W) und den δ-Ferritanteil von gepulsten WIG-Schweißungen des Stahls AISI 316L wurden untersucht. Die Grenzen für Unregelmäßigkeiten für die Qualitätsstufen der Schweißungen basierten auf der ISO-Norm 5817 B. Die Platten mit einer Dicke von 6 mm wurden in der Wannenposition auftragsgeschweißt. Ein zunehmender Wasserstoffanteil im Argon-Schutzgas erhöht das D/W-Verhältnis. Eine exzessive Wasserstoff-Zugabe führt zu einer vollständig gefüllten Nahtvorbereitung und einer exzessiven Durchschweißung. Die Erhöhung der Schweißgeschwindigkeit setzt das Schweißbadvolumen herab ebenso wie die D/W-Verhältnisse. Eine Stickstoff-Zugabe hat keine Auswirkungen auf das D/W-Verhältnis. Die Zugabe eines Stickstoff-Wasserstoff-Gemisches zum Argon-Schutzgas zeigte keine Wechselwirkung zwischen diesen und bezüglich des D/W-Verhältnisses. Eine Auswirkung auf das D/W-Verhältnis kann ausschließlich in Abhängigkeit des Wasserstoffgehalts beobachtet werden. Eine Erhöhung des Wasserstoffgehalts im Argon-Schutzgas erhöht den δ-Ferritanteil im Schweißgut. Eine Erhöhung entweder des Stickstoffgehalts oder der Schweißgeschwindigkeit setzt den δ-Ferritanteil im Schweißgut herab. Die Stickstoff-Zugabe erhöht den Stickstoffgehalt im Schweißgut, wenngleich eine Erhöhung der Wasserstoff-Zugabe zu einer Abnahme des Stickstoffgehalts im Schweißgut führt.

*Correspondence Address, Assoc. Prof. Dr. Gobboon Lothongkum, Innovative Metals Research Unit, Department of Metallurgical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand. E-mail:

Panyasak Phakpeetinan, born in 1980, received his Bachelor Degree in Production Technology from King Mongkut's University of Technology, North Bangkok, Thailand in 2004, and his Master Degree in Metallurgical Engineering from Chulalongkorn University, Bangkok, Thailand, in 2008. His research interest is welding of metals.

Dr. Amnuysak Chianpairot, is a researcher at the Failure Analysis and Surface Technology Lab, Materials Reliability Research Unit, National Metal and Materials Technology Center (MTEC), Pathaumthani, Thailand. He received his Master Degree in Metallurgical Engineering from University of California, Berkeley, USA, in 2001 and his PhD in Metallurgical Engineering from Chulalongkorn University, Thailand, in 2012. His research interests are corrosion and failure analysis.

Dr.-Ing. Ekkarut Viyanit, born in 1972, is a researcher and Head of the Failure Analysis and Surface Technology Lab, Materials Reliability Research Unit, National Metal and Materials Technology Center (MTEC), Pathaumthani, Thailand. He received his Dr.-Ing. Degree in Materials Engineering from Helmut-Schmidt University, Hamburg, Germany, in 2005. His areas of expertise include corrosion protection, failure analysis and joining of metals.

Prof. Dr.-Ing. Fritz Hartung is a visiting professor in the Department of Metallurgical Engineering, Faculty of Engineering, Chulalongkom University, Bangkok, Thailand. He received his Master and Dr.-Ing. Degrees in Mechanical Engineering from University of Technology Magdeburg, Germany, in 1969 and 1975, respectively. He was the Head of Department of Materials Technology and Welding, Trier University of Applied Science, Germany, from 1993 to 2010, and Professor at the University Dortmund, Germany, from 1993 to 2002. His areas of expertise are welding and metal joining.

Assoc. Prof. Dr.-Ing. Gobboon Lothongkum is a member of the Innovative Metals Research Unit, Associate Professor and Head of the Department of Metallurgical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand. He received his Dr.-Ing. Degree from Helmut Schmidt University of the Federal Armed Force in Hamburg, Germany, and the International Welding Engineer Certificate of the International Institute of Welding (IIW) in 1994 and 2006, respectively. His research interests are corrosion and welding of metals and alloys, development of stainless steels and high temperature materials.

References

1 N. N: World Stainless: Stainless Steel Specialist Course: Training Note 08, Welding and Joining of Stainless Steel, International Stainless Steel Forum, Brussels (2002) Search in Google Scholar

2 J.Norrish: Advanced Welding Process: Technologies and Process Control, Woodhead Publishing Limited, Cambridge, UK (2006) 10.1533/9781845691707 Search in Google Scholar

3 A.Durgutlu: Experimental investigation of the effect of hydrogen in argon as a shielding gas on TIG welding of austenitic stainless steel, Materials and Design25 (2004), pp. 19–2310.1016/j.matdes.2003.07.004. Search in Google Scholar

4 G.Lothongkum, P.Chaumbai, P.Bhandhubanyong: TIG pulse welding of 304L austenitic stainless steel in flat, vertical and overhead positions, Journal of Materials Processing Technology89–90 (1999), pp. 410–41410.1016/S0924-0136(99)00046-1 Search in Google Scholar

5 G.Lothongkum, E.Viyanit, P.Bhandhubanyong: Study on the effects of pulsed TIG welding parameters on delta-ferrite content, shape factor and bead quality in orbital welding of AISI 316L stainless steel plate, Journal of Materials Processing Technology110 (2001), No. 2, pp. 233–23810.1016/S0924-0136(00)00875-X Search in Google Scholar

6 J.Tušek: Experimental investigation of gas tungsten arc welding and comparison with theoretical predictions, IEEE Transaction on Plasma Sci.28 (2000), No. 5, pp. 1688–169310.1109/27.901255 Search in Google Scholar

7 S.Lu, H.Fujii, K.Nogi: Marangoni convection and weld shape variations in Ar-O2 and Ar-CO2 shielded GTA welding, Materials Science and Engineering A380 (2004), No. 1, pp. 290–29710.1016/j.msea.2004.05.057 Search in Google Scholar

8 S.Lu, H.Fujii, K.Nogi: Sensitivity of Marangoni convection and weld shape variations to welding parameters in O2-Ar shielded GTA welding, Scripta Materialia51 (2004), No. 3, pp. 271–27710.1016/j.scriptamat.2004.03.004 Search in Google Scholar

9 S.Lu, H.Fujii, K.Nogi: Influence of welding parameters and shielding gas composition on GTA weld shape, ISIJ International45 (2005), No. 1, pp. 66–7010.2355/isijinternational.45.66 Search in Google Scholar

10 S.Lu, H.Fujii, K.Nogi: Effects of CO2 shielding gas additions and welding speed on GTA weld shape, Journal of Materials Science40 (2005), No. 9–10, pp. 2481–248510.1007/s10853-005-1979-7 Search in Google Scholar

11 M.Du Toit, P. C.Pistorius: The influence of oxygen on the nitrogen content of autogenous stainless steel arc welds, Welding Journal86 (2007), No. 8, pp. 222s–230s Search in Google Scholar

12 S.Lu, H.Fujii, K.Nogi: Marangoni convection and weld shape variations in He-CO2 shielded gas tungsten arc welding on SUS304 stainless steel, Journal of Materials Science43 (2008), No. 13, pp. 4583–489110.1007/s10853-008-2681-3 Search in Google Scholar

13 A. B.Murphy, M.Tanaka, S.Tashiro, T.Sato, J. J.Lowke: A computational investigation of the effectiveness of different shielding gas mixtures for arc welding, Journal of Physics D: Applied Physics42 (2009), No. 11, Article No. 115205 10.1088/0022-3727/42/11/115205. Search in Google Scholar

14 J.Zähr, U.Füssel, M.Hertel, M.Lohse, M.Sende, M.Schnick: Numerical and experimental studies of the influence of process gases in TIG welding, Welding in the World56 (2012), No. 3–4, pp. 85–9210.1007/BF03321338 Search in Google Scholar

15 ISO 5817: 2007: Welding – Fusion-Welded Joints in Steel, Nickel, Titanium and their Alloys (Beam Welding Excluded) – Quality Levels for Imperfections, Beuth, Berlin, Germany (2007) Search in Google Scholar

16 F. C.Hull: Effect of delta ferrite on the hot cracking of stainless steel, Welding Journal, 46 (1967), No. 9, pp. 399s–409s Search in Google Scholar

17 W. T.Delong, G. A.Ostrom, E. R.Szumachowski: Measurement and calculation of ferrite in stainless steel weld metal, Welding Journal35 (1956), pp. 521s–528s Search in Google Scholar

18 J. F.Lancaster: Metallurgy of Welding, 5th Ed., Chapman and Hall, London, UK (1999) Search in Google Scholar

19 P.Phakpeetinan, N.Sornsuwit, S.Chandra-Ambhorn, G.Lothongkum: Effects of TIG Pulse Welding Parameters and Nitrogen Gas Mixed in Argon Shielding Gas on Weld Bead Formation and Microstructure of Weld Metals of AISI 304L Stainless Steels at 10 h Welding Position, Proc. of the 86th AWS Annual Convention, Session PE3, Dallas, Texas, USA (2005) Search in Google Scholar

20 R. K.Okagawa, R. D.Dixon, D. L.Olson: The influence of nitrogen from welding on stainless steel weld metal microstructure, Welding Journal62 (1983), No. 8, pp. 204s–208s Search in Google Scholar

21 T.Ogawa, K.Suzuki, T.Zaizen: The weldability of nitrogen-containing austenitic stainless steel: Part II – Porosity cracking and creep properties, Welding Journal63 (1984), No. 7, pp. 213s–223s Search in Google Scholar

22 T.Ogawa, T.Koseki: Weldability of newly developed austenitic alloys for cryogenic service: Part II – High-nitrogen stainless steel weld metal, Welding Journal67 (1988), No. 1, pp. 8s–17s Search in Google Scholar

23 S.Hertzman, R. JargeliusPettersson, R.Blom, E.Kivineva, J.Eriksson: Influence of shielding gas composition and welding parameters on the Ncontent and corrosion properties of welds in N-alloyed stainless steel grades, ISIJ International36 (1996), No. 7, pp. 968–97610.2355/isijinternational.36.968 Search in Google Scholar

24 D. R.Lide (Ed.): CRC Handbook of Chemistry and Physics, 84th Ed., CRC Press, Boca Raton, FL, USA (2003) Search in Google Scholar

25 I.Woo, Y.Kikuchi: Weldability of high nitrogen stainless steel, ISIJ International42 (2002), No. 12, pp. 1334–134310.2355/isijinternational.42.1334 Search in Google Scholar

26 R.Mundt, H.Hoffmeister: Continuous delta – gamma transformation during cooling of ferritic-austenitic iron-chromium-nickel alloys, Steel Research54 (1983), No. 8, pp. 333–336 Search in Google Scholar

27 A.Wessel, F.Erdmann-Jesnitzer: Wasserstoffversprödung kubisch-flächenzentrierter Werkstoffe, D.Kuron (Ed.): Wasserstoff und Korrosion, Verlag Irene Kuron, Germany (1986), pp. 204–238 Search in Google Scholar

28 N.Suutala: Effect of solidification conditions on the solidification mode in austenitic stainless steels, Metallurgical Transactions A14 (1983), No. 1, pp. 191–19710.1007/BF02651615 Search in Google Scholar

29 V.Shankar, T. P. S.Gil, S. L.Mannan, S.Sundaresan: Effect of nitrogen addition on microstructure and fusion zone cracking in type 316L stainless steel weld metals, Material Science and Engineering A343 (2003), No. 1–2, pp. 170–18110.1016/S0921-5093(02)00377-5 Search in Google Scholar

30 B.Zorc: Automatic TIG welding of austenitic stainless steels in nitrogen and nitrogen-based gas mixtures, Revista de Metalurgia4 (2011), No. 1, pp. 29–3710.3989/revmetalmadrid.0962 Search in Google Scholar

Published Online: 2016-05-23
Published in Print: 2016-06-01

© 2016, Carl Hanser Verlag, München

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Materials Testing
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Volume 58 Issue 6

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