Investigation of heat transfer and fluid flow in activating TIG welding by numerical modeling

Abstract

Heat transfer and fluid flow of arc plasma and weld pool in tungsten inert gas (TIG) welding and activated flux tungsten inert gas (A-TIG) welding of SUS 304 stainless steel are investigated comparatively though a 3D unified model. The model differs from the previous ones in that it considers the arc length more realistic for welding production. Tungsten electrode, anode (work piece) and arc plasma are all included. The effects of buoyance, plasma drag force, Lorentz force and Marangoni force on the weld pool flow are taken into account. By solving the conservation equations of mass, momentum, energy as well as Maxwell equations, the distributions of temperature and velocity of arc plasma and weld pool are obtained for TIG and A-TIG welding. The heat flux, current density and shear stress at the

Microstructural Characterization of TiC-Reinforced Metal Matrix Composites Fabricated by Laser Cladding Using FeCrCoNiAlTiC High Entropy Alloy Powder

“…The reinforcing particles are grown or dissolved through interaction with the liquid metal moving with the molten pool flow, and the final cladding layer is formed with the solidification by cooling. In the case of gas tungsten arc process, heat transfer occurs due to conduction and convection, and the molten pool is driven due to the various effects of the electromagnetic force, buoyancy force, arc drag force, and surface tension [24]. In the arc process, since the reinforcing particles were not mixed in the depth direction, and the flow at the surface was governed by the driving forces, it was difficult to distribute the reinforcing particles homogeneously in the depth direction [8,25].…”

Development of a novel GTAW process for joining ultra-thin metal sheets

“…Typically, the arc length in the conventional GTAW process is challenging to set up at less than one millimeter. This is because the metal evaporation from the weld pool encloses the tungsten electrode tip to make a short-circuit, and molten pool surface fluctuation is too large [30,31]. However, in the novel technology, the arc length can be set up at extremely short distances by reducing the evaporation from the molten pool and the contamination of the tungsten electrode surface.…”

Improving Welding Penetration and Mechanical Properties via Activated-Flux Smearing by Tungsten Inert Gas Arc Welding

“…Achieving an appropriate ferrite-to-austenite phase ratio is a crucial determinant of the welded joint's mechanical properties [10,[19][20][21]. In the context of stainless-steel thick-walled structural components, A-TIG welding primarily counters the Marangoni convection within the molten pool, significantly augmenting weld penetration and thereby reducing the width of the heat-affected zone [22][23][24]. Simultaneously, mechanical properties like tensile strength and hardness exhibit minimal alterations [25,26].…”