EFFECT OF VARIOUS DRIVING FORCES ON HEAT AND MASS-TRANSFER IN ARC-WELDING

In this study the heat transfer and fluid flow of the molten pool in s tationary gas tungsten are welding using argon shielding gas were inve stigated. Transporting phenomena from the welding are to the base mate rial surface, such as current density, heat flux, arc pressure, and sh ear stress acting on the weld pool surface, were taken from the simula tion results of the corresponding welding arc. Various driving forces for the weld pool convection were considered: self-induced electromagn etic, surface tension, buoyancy, and impinging plasma arc forces. Furt hermore, the effect of surface depression due to the arc pressure acti ng on the molten pool surface was considered. Because the fusion bound ary has a curved and unknown shape during welding, a boundary-fitted c oordinate system was adopted to precisely describe the boundary for th e momentum equation. The numerical model was applied to AISI 304 stain less steel and compared with the experimental results.