Unsteady marangoni flow in a molten pool when welding dissimilar metals. Modelling of gas tungsten arc welding pool under marangoni. Pdf visualization of marangoni convection in simulated weld. In weld pools, temperature gradients also lead to density gradients, which give rise to buoyancy effects. When the base metal during welding reaches its melting point, a weld pool forms. The effect of oxygen on transitional marangoni flow in laser spot welding. The flow without a surfaceactive agent is illus weld. Marangoni convection and weld shape variation in atig welding. Weld penetration and marangoni convection with oxide fluxes in. Marangoni convection in a weld pool of a surfaceactive agent can make the without a surfaceactive agent. Pdf the effect of oxygen on transitional marangoni flow in laser. In simulations of conventional electric arc welding and laser heat conduction welding, the effect of the temperaturedependent coefficient of surface tension marangoni effect has been identified as one of the primary driving forces of the liquid melt.
Marangoni effect in laser deep penetration welding of. It is shown that for normal gtatig welding conditions the heipleroper theory is valid, i. The flux effect on tig weld shape variations is investigated by application of the heat transfer and fluid flow model. Visualization of marangoni convection in simulated weld pools. Unsteady marangoni flow in a molten pool when welding dissimilar. Effects of atig welding on weld shape, mechanical properties, and corrosion resistance of 430 ferritic stainless steel alloy. Marangoni effects in welding philosophical transactions. Marangoni forces within these pools can affect the flow and temperature distribution and modify the molten pool extension. Marangoni effects in welding philosophical transactions of the.
Marangoni effect in laser deep penetration welding of steel article in journal of laser applications 5. So, the arcs will deflect to the side without flux where the electric resistance is lower. Users may download and print one copy of any publication from the. In laser deep penetration welding simulations this effect has been widely neglected, so far. Marangoni effect only depends on the surface tension gradient in the water and does not rely on the absolute values of the surface tension or ipa concentration of the ipawater mixture. The surface tension gradient is mainly controlled by the oxygen content in the weld pool, which determines the marangoni convection and penetration depth. Effects of different activating fluxes on the surface tension of molten. Publishers pdf, also known as version of record includes final page. Since a liquid with a high surface tension pulls more strongly on the surrounding liquid than one with a low. Welding is a fabrication process where the marangoni effect has to be accounted for. The marangoni effect is the mass transfer along an interface between two fluids due to the surface tension gradient. Pdf marangoni convection and welding penetration in atig. In the case of temperature dependence this phenomenon may be called thermocapillary convection.
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