Numerical analysis of arc driving forces and temperature distribution in pulsed TIG welding

Abstract

In order to study the influence of each driving force on the flow of molten pool and its influence degree, separate action models for the arc driving forces were established based on the finite difference method. It is found that the descending order of the driving force influence is surface tension, arc pressure, Lorentz force, drag force and buoyancy when the current is a constant value of 200 A. Based on the calculation of arc driving forces, a transient three-dimensional model of the pulsed TIG welding is established. The alternation of peak current and base current leads to periodic oscillation of molten pool surface and the formation of welding ripples. The results show that the distance between adjacent welding ripples is almost directly proportional to the scanning speed and the molten pool depth decreases with increasing speed and the decreasing speed gradually decreases. By studying the distribution of pressure field and temperature field, it is found that the pressure distribution of a semi-arc column is basically a half-Gaussian distribution and the heat accumulation has a significant effect on the maximum temperature of the substrate.

Microstructure and Mechanical Properties of Fe-36Ni and 304L Dissimilar Alloy Lap Joints by Pulsed Gas Tungsten Arc Welding

“…Fe-36Ni and 304L have thermal conductivity, and the heat accumulation makes the temperature of the base material gradually increase with the progress of welding [ 33 ], which resulting in weld center can maintain a high temperature for a long time. So that the composition fluctuation at the boundary of cell crystal is large enough, and the carbide is enough to nucleate, so that a large number of precipitations occur.…”

Numerical Study on Thermodynamic Behavior during Selective Laser Melting of 24CrNiMo Alloy Steel

“…The physical properties of 24CrNiMo alloy steel vary significantly with temperature, which should be considered in the simulation. In this paper, the temperature-dependent physical properties of 24CrNiMo alloy steel in solid state are obtained by the commercial software JMatPro (version 9.0, Sente Software Ltd., Surrey, UK ), which is a powerful and integrated software for material properties simulation [18][19][20], as shown in Figure 3.…”

The Problem of Selecting the Parameters of the Numerical Model of the Heating Process with a Point Heat Source and Its Experimental Verification

“…Among the high-temperature heat sources, the processes associated with the Tungsten Inert Gas (TIG) method and its wide range of modifications occupy an important place [ 10 ]. The TIG method is used in research work and described in the vast majority of cases with remelting, often assisted by additional substances or modifications to the method and considered due to the analysis of the behaviour of the remelted area [ 11 ].…”