The Effect of Buoyancy-Induced Force on Weld Zone Geometry During Spot GTA Welding

This fundamental research work is carried out to better understand the role of the weld pool convection during arc welding process. The effect of simulated buoyancy convection on weld pool shape and size in spot GTA welding of 2205 duplex stainless steel is evaluated experimentally and numerically in this paper.  Various simulated gravity conditions are applied in experimental welding process using the Multi-Gravity Research Welding System which is a centrifuge designed at Clarkson University for the study of welding under simulated high gravity condition. As a result of altering gravity condition (g-level), buoyancy force changes in the weld pool thus the overall convection alters. The change in the overall weld pool convection in turn changes the weld zone geometry as well as the quality.

The same condition is simulated numerically through finite element analysis software COMSOL Multiphysics. 2-D axisymmetric fluid flow and temperature field in weld pool are modeled for different g-levels to determine the effect of high gravity on the weld zone shape and profile.

The results are compared to those of experimental study and a good agreement is observed.