Toward a validation of coupled arc-melt pool model for a TIG spot weld configuration

Abstract The TIG process is a complex arc welding method due to the multitude of operating parameters and their interdependence, making it challenging to master. To improve understanding of it, a magneto-thermo-hydrodynamic model with arc-melt pool coupling is realized. A comparison is made between numerical and exhaustive experimental results of welding performed on 304L stainless steel in spot configuration at $$150~\text{A}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>150</mml:mn> <mml:mspace/> <mml:mtext>A</mml:mtext> </mml:mrow> </mml:math> and $$250~\text{A}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>250</mml:mn> <mml:mspace/> <mml:mtext>A</mml:mtext> </mml:mrow> </mml:math> . The effect on the melt pool of increasing the intensity is numerically studied and compared to experimental trends. A significant reduction of the model error is observed when considering the deformation of the anode-plasma interface, which strongly impacts the arc and the melt pool at high intensity. However, the numerical melt pool size is still underestimated compared to the melt areas observed on the post-mortem micrographs. The effect of an additional potential drop term that can be found in the literature is studied and demonstrated to be ineffective. The experimental melt area overestimation is discussed to explain the differences observed.