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GMA welding metal transfer mode study by high-speed imaging and electrical signal acquisition

  • Gustavo Simões TeixeiraEmail author
  • José Antônio Esmerio Mazzaferro
Technical Paper
  • 26 Downloads

Abstract

Weld metal transfer modes in gas metal arc welding process have an important role in electric arc stability, in the amount of absorbed gases by the melted metal in weld pool, allow out-of-position welding and influence in sparkles generation. The objective of the present work is to obtain images of the metal transfer to the weld pool, in order to better characterize the transfer mode boundaries. Besides, electric signals of welding current and voltage were acquired and compared with the generated images to confirm the results. High-speed imaging helps to identify the weld metal transfer mode. In this work, a high-speed camera and filter lenses were used to get images and movies of welding arcs generated by three different AWS ER70S-6 wire diameters (0.8, 1.0 and 1.2 mm). Also, different shielding gases and mixtures were tested (Ar, Ar + 2% O2, Ar + 10% CO2, Ar + 25% CO2 and CO2). Metal transfer modes could be observed at a frame rate of 5000 fps. Metal transfer mode maps were plotted to identify regions of each kind of metal transfer. Interchangeable globular/spray metal transfer occured in some cases of cyclic alternation between globular and spray transfer during the welding.

Keywords

Weld metal Metal transfer Analysis techniques GMA welding Arc welding Imaging 

Notes

Acknowledgements

The authors would like to thank the Welding and Related Techniques Laboratory (LS&TC) for the equipment used in this work (welding sources, welding consumables, data acquisition system, CNC welding system) and the Graduate Program in Mechanical Engineering (PROMEC) for the high-speed camera and lenses borrowing. No funds or grants were received for this work.

References

  1. 1.
    Greene WJ (1960) An analysis of transfer in gas-shielded welding arcs. Trans Am Inst Electr Eng 2:194–203Google Scholar
  2. 2.
    Amson JC (1965) Lorentz force in the molten tip of an arc electrode. Br J Appl Phys 16:1169–1179CrossRefGoogle Scholar
  3. 3.
    International Institute of Welding (1976) Classification of Metal Transfer, IIW Doc. XII-636-76Google Scholar
  4. 4.
    Lancaster JF (1986) The physics of welding, 2nd edn. The International Institute of Welding, Pergamon Press, Headington Hill Hall, OxfordGoogle Scholar
  5. 5.
    Scotti A, Ponomarev V, Lucas W (2012) A scientific application oriented classification for metal transfer modes in GMA welding. J Mater Process Technol 212:1406–1413CrossRefGoogle Scholar
  6. 6.
    Norrish J (2003) A review of metal transfer classification in arc welding, IIW Doc. XII-1769-03Google Scholar
  7. 7.
    Lucas W, Iordachescu D, Ponomarev V (2005) Classification of metal transfer modes in GMAW, IIW Doc. XII-1859-05Google Scholar
  8. 8.
    Iordachescu D, Quintino L (2008) Steps toward a new classification of metal transfer in gas metal arc welding. J Mater Process Technol 202:391–397CrossRefGoogle Scholar
  9. 9.
    Needham JC, Cooksey CJ, Milner DR (1960) Metal transfer in inert-gas shielded arc-welding. Br Weld J 7(2):101–114Google Scholar
  10. 10.
    Pintard J (1966) Formation et croissance des gouttes. Forces auxquelles elles sont surmises avant et pendant le transfer. IIW Doc. 212-89-66Google Scholar
  11. 11.
    Breymeier RT (1952) Metal transfer in sigma welding. Weld J 31:393–398Google Scholar
  12. 12.
    Smith AA (1966) Characteristics of the short-circuiting CO2—shielded arc. Physics of the Welding Arc, Institute of Welding, pp 75–91Google Scholar
  13. 13.
    Liu S, Siewert TA (1989) Metal transfer in gas metal arc welding droplet rate. Weld J 02:52–58Google Scholar
  14. 14.
    Heald PR, Madigan RB, Siewert TA, Liu S (1994) Mapping the droplet transfer modes for an ER100S-1 GMAW electrode. Weld J 02:38–44Google Scholar
  15. 15.
    Bálsamo PSS, Vilarinho LO, Vilela M, Scotti A (2000) Development of an experimental technique for studying metal transfer in welding: synchronized shadowgraphy. Int J Join Mater 12:1–12Google Scholar
  16. 16.
    Scotti A, Ponomarev V, Lucas W (2014) Interchangeable metal transfer phenomenon in GMA welding: features, mechanisms, classification. J Mater Process Technol 214:2488–2496CrossRefGoogle Scholar
  17. 17.
    Hu S, Zhang H, Wang Z, Liang Y, Liu Y (2016) The arc characteristics of cold metal transfer welding with AZ31 magnesium alloy wire. J Manuf Process 24:298–306CrossRefGoogle Scholar
  18. 18.
    Zhao Y, Shi X, Yan K, Wang G, Jia Z, He Y (2018) Effect of shielding gas on the metal transfer and weld morphology in pulsed current MAG welding of carbon steel. J Mater Process Technol 262:382–391CrossRefGoogle Scholar
  19. 19.
    Freeman JJ, Eagar TW (1992) An investigation of gas metal arc welding of steel in pure argon. Interim Report, Materials Processing Center, Massachusetts Institute of Technology, Cambridge, MassachusettsGoogle Scholar
  20. 20.
    Jönsson PG (1993) Arc properties and metal transfer in gas metal arc welding. D. Sc. Dissertation, Massachusetts Institute of Technology, Cambridge, MassachusettsGoogle Scholar
  21. 21.
    Jönsson PG, Murphy AB, Szekely J (1995) The influence of oxygen additions on argon-shielded gas metal arc welding processes. Weld J 02:48–58Google Scholar

Copyright information

© The Brazilian Society of Mechanical Sciences and Engineering 2019

Authors and Affiliations

  1. 1.Instituto Federal de Educação Ciência e Tecnologia do Rio Grande do Sul – Campus Rio GrandeRio GrandeBrazil
  2. 2.Universidade Federal do Rio Grande do SulPorto AlegreBrazil

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