2020 Volume 38 Issue 2 Pages 54s-58s
Workpiece vibration has been applied during arc welding to make weld metal microstructure fine and reduce weld defects such as the blow holes. It was unexpectedly found that the continuous workpiece vibration utilizing a sine component with a specific frequency parallel to welding direction changed the penetration shape from finger-shape to pan-bottom shape in the pulsed metal active gas welding via 18% of CO2 shielding gas. A coupled Eulerian Lagrangian finite element model was employed especially for adding workspace vibration to the fluid flow of molten materials. The velocity ofmolten materials through the designated zone of the weld pool was investigated with and without the workpiece vibration. The simulation suggests that increase in the fluid flow velocity along the welding direction at a specific frequency of workpiece vibration led to bringing the high-temperature material to the position where the final penetration shape was determined. Consequently, the penetration bottom would be widened and the middle of fusion line would be deepened, leading to penetration shape change to relatively pan-bottom shape.
