Numerical simulation study of the effect of weld current on WAAM welding pool dynamic and weld bead morphology

The welding current has the direct effect on the heat and mass transfer and the weld bead morphology in the WAAM process. In order to reveal its action mechanism, a three-dimensional transient simulation model is established to study the molten pool dynamic and the weld bead morphology of WAAM single-bead deposition process. The simulation results show that the volume of the molten pool increases as the weld current. The action of the surface tension and arc pressure result in the temperature of molten pool augment with the rise of current. Under the action of temperature gradient, the convection of the molten pool intensifies as the weld current increases. In terms of the weld bead forming, the bead width increases while the height decreases with the increase of current, and the width-height rate increases monotonically. The simulated cross-sectional profile of single-bead accords well with experimental results, which indicates that the numerical model established in this paper is effective and convincing.