Properties of Mass and Heat Transfer for Tube Cathode Arcs

Abstract

Since Tungsten Inert Gas (TIG) arc enables to produce arc plasma with high energy density, it is suitable as a heat source especially for processes to require concentrating the heat input at a point. On the other hand, Tube Cathode Arc (TCA) to be a kind of TIG produces the arc plasma by introducing shielding gas through the central hole of the tube cathode. In the present paper, basic heat source property of argon TCA at the atmospheric pressure was numerically analyzed and compared with that for the conventional TIG arc. As a result, it was found that TCA is suitable for processes such as brazing or buildup, since it enables to heat a target material uniformly by controlling inner shielding gas flow rate. Furthermore, TCA is expected to realize high-speed welding because the arc pressure to a base metal reaches only 30% of TIG due to lower current density.

Arc physics based heat source modelling for numerical simulation of weld residual stress and distortion

“…The ion current density j i is then assumed to be j i 5j2j R , where the total current density j is j5j i zj e . The governing and auxiliary equations are solved iteratively by the numerical procedure, 9,10 and the other approximation and boundary conditions are given in previous papers. [14][15][16] Effect of welding conditions on TIG arc heat source…”

“…Clearly, a more detailed consideration of the temperature distribution is required for more accurate prediction and control of weld distortion. Arc plasma simulations [3][4][5][6][7][8][9][10][11][12][13] based on mathematical modelling of the heat transfer from arc plasma to a welded plate are one of the reliable methods to consider accurate temperature distributions during welding.…”

A Numerical Model with arc length variation of welding arc with constant voltage power source

“…And the electrodes properties are given in 10). The other approximations, governing equations and boundary conditions are given in detail in our previous papers 6,11,12) . Figures 3 and 4 show calculated results of temperature fields for the CV power source and the CC power source at 0.15 s and 0.2 s after arc ignitions.…”

Numerical Analysis of Metal Vapor Behavior with Multi-diffusion System in TIG Welding of Stainless Steel

“…where p atm is atmospheric pressure and p v,i is the partial pressure of metal vapor, which is a function of the weld pool temperature 12) , and n i is mol fraction of a metal in stainless steel. The other approximations, governing equations and boundary conditions are given in detail in our previous papers 4,14) . The governing and auxiliary equations are solved iteratively by the SIMPLEC numerical procedure.…”