Current numerical models of gas metal arc welding（GMAW）are trying to combine magnetohydrodynamics （MRD） models of the arc and voiume of fluid （VoF） models of metal transfer They neglect vaporization and assume a...Current numerical models of gas metal arc welding（GMAW）are trying to combine magnetohydrodynamics （MRD） models of the arc and voiume of fluid （VoF） models of metal transfer They neglect vaporization and assume an argon atmosphere for the arc region, as it is common practice for models of gas tungsten arc welding, These models predict temperatures above 20 000K anda temperature distribution similar to tungsten inert gas （TIG） arcs： However. current spectroscopic temperature measuretemperatures. In contrast to TIG arcs temperature distrbution. The paper vapour and which is in a yery good res, Futhermore; the model is abile 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 work piece, 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 2000 to 5000 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, and the evaporation rate relative to the wire feed. Finally the model predictions are compared with the measuring results of Zielihska et al.展开更多
文摘Current numerical models of gas metal arc welding（GMAW）are trying to combine magnetohydrodynamics （MRD） models of the arc and voiume of fluid （VoF） models of metal transfer They neglect vaporization and assume an argon atmosphere for the arc region, as it is common practice for models of gas tungsten arc welding, These models predict temperatures above 20 000K anda temperature distribution similar to tungsten inert gas （TIG） arcs： However. current spectroscopic temperature measuretemperatures. In contrast to TIG arcs temperature distrbution. The paper vapour and which is in a yery good res, Futhermore; the model is abile 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 work piece, 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 2000 to 5000 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, and the evaporation rate relative to the wire feed. Finally the model predictions are compared with the measuring results of Zielihska et al.
