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Zacharia, T.; David, S. A.; Vitek, J.M.; Kraus, Hal G.

doi:10.1007/bf02659142

Cited by 8 publications

(16 citation statements)

References 2 publications

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“…MODEL OF TIG WELDING PROCESS Modeling the arc-welding process has been tried by a number of researchers. [2][3][4][5][6][7][8][9][10][11][12][13][14][15] However, almost every numeri-A. Governing Equations cal model has treated either only the arc plasma [3][4][5][6][7][8] or only…”

Section: Introductionmentioning

confidence: 99%

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A unified numerical modeling of stationary tungsten-inert-gas welding process

Tanaka

Terasaki

Ushio

et al. 2002

Metall Mater Trans A

163

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In order to clarify the formative mechanism of weld penetration in an arc welding process, the development of a numerical model of the process is quite useful for understanding quantitative values of the balances of mass, energy, and force in the welding phenomena because there is still lack of experimentally understanding of the quantitative values of them because of the existence of complicated interactive phenomena between the arc plasma and the weld pool. The present article is focused on a stationary tungsten-inert-gas (TIG) welding process for simplification, but the whole region of TIG arc welding, namely, tungsten cathode, arc plasma, workpiece, and weld pool is treated in a unified numerical model, taking into account the close interaction between the arc plasma and the weld pool. Calculations in a steady state are made for stationary TIG welding in an argon atmosphere at a current of 150 A. The anode is assumed to be a stainless steel, SUS304, with its negative temperature coefficient of surface tension. The two-dimensional distributions of temperature and velocity in the whole region of TIG welding process are predicted. The weld-penetration geometry is also predicted. Furthermore, quantitative values of the energy balance for the various plasma and electrode regions are given. The predicted temperatures of the arc plasma and the tungsten-cathode surface are in good agreement with the experiments. There is also approximate agreement of the weld shape with experiment, although there is a difference between the calculated and experimental volumes of the weld. The calculated convective flow in the weld pool is mainly dominated by the drag force of the cathode jet and the Marangoni force as compared with the other two driving forces, namely, the buoyancy force and the electromagnetic force.

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Section: Introductionmentioning

confidence: 99%

“…[2,[9][10][11][12][13] Then, calculated predictions, for examrelative to a cylindrical coordinate, assuming rotational symple, for the weld pool, require distributions of heat flux and metry around the arc axis. The calculation domain is shown in Figure 2.…”

Section: Introductionmentioning

confidence: 99%

A unified numerical modeling of stationary tungsten-inert-gas welding process

Tanaka

Terasaki

Ushio

et al. 2002

Metall Mater Trans A

163

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“…The gradient of surface tension with respect to temperature has been assumed as a positive constant equal to 10 -5 N/mK for temperatures less than 2200 K and a negative constant equal to -10 -5 N/mK for higher temperatures. [9,17,21] The arc efficiency (g) is 80 pct, [11] the arc radius (r b ) for heat distribution is 0.003 m, and the arc radius for current distribution (r j ) is 0.003 m. The properties of material used in the computations are given in Table II.…”

Section: Numerical Solution Proceduresmentioning

confidence: 99%

“…Temperature and velocity fields were calculated for both stationary and linear welding. A comparison between the calculated and experimental results for spot and linear GTA welding of stainless steel was made by Zacharia et al [9][10][11] Fan et al [12] predicted the temperature, velocity, and free surface deformation for a partially or fully penetrated weld pool in stationary GTA welding, using an axisymmetric heat and fluid flow model.…”

Section: Introductionmentioning

confidence: 99%

Modeling of Linear Gas Tungsten Arc Welding of Stainless Steel

Ponnambalam¹,

Sornakumar²,

Sundararajan

2008

Metall Mater Trans B

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A heat and fluid flow model has been developed to solve the gas tungsten arc (GTA) linear welding problem for austenitic stainless steel. The moving heat source problem associated with the electrode traverse has been simplified into an equivalent two-dimensional (2-D) transient problem. The torch residence time has been calculated from the arc diameter and torch speed. The mathematical formulation considers buoyancy, electromagnetic induction, and surface tension forces. The governing equations have been solved by the finite volume method. The temperature and velocity fields have been determined. The theoretical predictions for weld bead geometry are in good agreement with experimental measurements.

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“…The behaviour of an arc is governed by a coupled set of physical laws, i.e., Ohm's Law, Maxwell's equations and conservation equations of mass, momentum, energy and electrical charge [1,2]. The modelling of arc welding processes has been reported by a number of researchers [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Most early numerical models have treated either only the arc plasma [2][3][4][5][6][7] or only the weld pool [8][9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Theoretical model and experimental investigation of current density boundary condition for welding arc study

Boutaghane

Bouhadef

Valensi

et al. 2011

Eur. Phys. J. Appl. Phys.

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Abstract. This paper presents results of theoretical and experimental investigation of the welding arc in Gas Tungsten Arc welding (GTAW) and Gas Metal Arc Welding (GMAW) processes. A theoretical model consisting in simultaneous resolution of the set of conservation equations for mass, momentum, energy and current, Ohm's law and Maxwell equation is used to predict temperatures and current density distribution in argon welding arcs. A current density profile had to be assumed over the surface of the cathode as a boundary condition in order to make the theoretical calculations possible. In stationary GTAW process, this assumption leads to fair agreement with experimental results reported in literature with maximum arc temperatures of ~ 21000 K. In contrast to the GTAW process, in GMAW process, the electrode is consumable and non-thermionic, and a realistic boundary condition of the current density is lacking. For establishing this crucial boundary condition which is the current density in the anode melting electrode, an original method is setup to enable the current density to be determined experimentally. High-speed camera (3000 images/sec) is used to get geometrical dimensions of the welding wire used as anode. The total area of the melting anode covered by the arc plasma being determined, the current density at the anode surface can be calculated. For a 330 A arc, the current density at the melting anode surface is found to be of 5×10 7 A.m -2 for a 1.2 mm diameter welding electrode. IntroductionIn arc welding, an electric arc is burning between a "workpiece" and an auxiliary electrode: -For gas metal arc welding (GMAW) process the auxiliary electrode is welding wire, which is usually the anode (reverse polarity). Heat transfer from the arc and Ohm's heating in the wire melt its tip forming droplets, transferred through the arc to the workpiece used as a cathode. -For gas tungsten arc welding (GTAW) process, the workpiece, which is usually the anode (straight polarity), locally melts due to heat transfer from the arc, forming a weld pool. Thermal behaviour of welding arcs and their electrodes can have significant effects on the subsequent weld quality and production rate. Hence, it is desirable to have a theoretical method which can predict the properties of both electrodes and arc plasma as functions of the arc operating conditions. The behaviour of an arc is governed by a coupled set of physical laws, i.e., Ohm's Law, Maxwell's equations and conservation equations of mass, momentum, energy and electrical charge [1,2]. The modelling of arc welding processes has been reported by a number of researchers [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Most early numerical models have treated either only the arc plasma [2][3][4][5][6][7] or only the weld pool [8][9][10][11][12][13][14]. For the arc plasma, a plane surface of the solid anode has been set to be a bottom boundary for the electric potential and temperature which are given as the boundary conditions. The tungsten cathode has been assumed to be a...

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Cited by 8 publications

References 2 publications

A unified numerical modeling of stationary tungsten-inert-gas welding process

A unified numerical modeling of stationary tungsten-inert-gas welding process

Modeling of Linear Gas Tungsten Arc Welding of Stainless Steel

Theoretical model and experimental investigation of current density boundary condition for welding arc study

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