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Welding in the World

, Volume 55, Issue 11–12, pp 114–120 | Cite as

Numerical Investigations of the Influence of Metal Vapour in GMA Welding

  • Michael Schnick
  • Uwe Füssel
  • Martin Hertel
  • Sascha Rose
  • Martin Haessler
  • Andreas Spille-Kohoff
  • Anthony B. Murphy
Peer-Reviewed Section

Abstract

Current numerical models of gas metal arc welding (GMAW) attempt to combine a magnetohydrodynamic (MHD) model of the arc and a volume-of-fluid (VoF) model of metal transfer. But in these models vaporization of metal is neglected and the arc region is assumed to be composed of pure argon, as it is common practice for models of gas tungsten arc welding (GTAW). These models predict temperatures over 20 000 K and a temperature distribution similar to GTAW arcs. However, recent spectroscopic temperature measurements in GMAW arcs have demonstrated much lower arc temperatures. In contrast to GTAW arcs, they found a central local minimum of the radial temperature distribution. The paper presents a GMAW arc model that considers metal vapour and which is in very good agreement with experimentally observed temperatures. Furthermore, the model is able to predict the local central minimum in the radial temperature and the radial electric current density distributions for the first time. The axially symmetric model of the welding torch, the workpiece, the wire and the arc (fluid domain) implements MHD as well as turbulent mixing and thermal demixing of metal vapour in argon. The mass fraction of iron vapour obtained from the simulation shows an accumulation in the arc core and another accumulation on the fringes of the arc at 2 000 to 5 000 K. The demixing effects lead to very low concentrations of iron between these two regions. Sensitive analyses demonstrate the influence of the transport and radiation properties of metal vapour, the welding current and the evaporation rate.

IIW-Thesaurus keywords

Argon Diffusion Evaporation GMA welding Plasma Radiation Simulating 

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Copyright information

© International Institute of Welding 2011

Authors and Affiliations

  • Michael Schnick
    • 1
  • Uwe Füssel
    • 1
  • Martin Hertel
    • 1
  • Sascha Rose
    • 1
  • Martin Haessler
    • 1
  • Andreas Spille-Kohoff
    • 2
  • Anthony B. Murphy
    • 3
  1. 1.Technische Universität DresdenDresdenGermany
  2. 2.CFX Berlin Software GmbHBerlinGermany
  3. 3.CSRIO Materials Science and EngineeringSydneyAustralia

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