Effect of different electrode tip angles with tilted torch in stationary gas tungsten arc welding: A 3D simulation

Abstract

In this study, the effect of different tip angles (30 , 60 , 90 and 120) on the arc and weld pool behavior is analyzed in 2 mm and 5 mm arc lengths with tilted (70) torch. Arc temperature, velocity, current density, heat flux and gas shear are investigated in the arc region and pool convection and puddle shapes are studied in the weld pool region. The arc temperature at the tungsten electrode is found the maximum with sharp tip and decreases as the tip angle increases. The arc temperature on the anode (workpiece) surface becomes concentrated with increase in tip angle. The arc velocity and gas shear stress are observed large with sharp tip and decreasing as the tip angle increases. Current density on the anode surface does not change with tip angle and observed almost the same in all the tip angles in both 2 mm and 5 mm arc lengths. Heat flux due to conduction and convection is observed more sensitive to the tip angle and decreases as the tip angle increases. The electromagnetic force is slightly observed increasing and the buoyancy force is observed slightly decreasing with increase in tip angle. Analyzing each driving force in the weld pool individually shows that the gas drag and Marangoni forces are much stronger than the electromagnetic and buoyancy forces. The weld pool shape is observed wide and shallow in sharp and narrow and deep in large tip angle. Increasing the arc length does not change the weld pool width; however, the weld pool depth significantly changes with arc length and is observed deep in short arc length. The arc properties and weld pool shapes are observed wide ahead of the electrode tip in the weld direction due to 70 torch angle. Good agreement is observed between the numerical and experimental weld pool shapes.

Influence of Welding Parameters on the Weld Pool Dimensions and Shape in a TIG Configuration

“…The main differences in our cases are from 2 s up to 20 s. Our experimental width evolutions during the first second for the two angles are included in the error bars and weak differences appear. Nevertheless, from 2 s up to 20 s our conclusion is consistent with the behaviour found by Goodarzi et al Other theoretical results exist on the influence of the value of the cathode tip angles, such as for instance the paper presented by Abid et al [23], however in those cases the torch position is not vertical (70 • ) and the model is stationary. Figure 7a presents the depth-to-width ratio for two cathode tip angles.…”

Transient Finite Element Simulation and Microstructure Evolution of Aa2219 Weld Joint Using Gas Tungsten Arc Welding Process

“…The computed weld pool shapes are observed wide and shallow with small and narrow and deep with large electrode tip angle. The computed pool shapes are compared with the experimental results and are observed in good agreement [13]. The FEM dynamic heat source model was used to simulate the low frequency PCGTAW, which has successfully demonstrated the dynamic temperature field in the welding process.…”

Modeling residual stresses of functionally graded deposits using the PTAAM

“…In this work a sharp thoriated tungsten electrode of 3.2mm diameter with 20° angle tip is used. For such an electrode, the value of current density is 1x10 8 A/m 2 for a 5mm long arc [7]. In Table 2 are shown some central velocity predictions made using this calculation method.…”