Higher Droplet Rate and Improved Metallurgical Properties in GMA Welding through External Magnetic Field

Applications of external magnetic fields to welding processes are used to induce disturbances in the arc and weld pool. As a result arc deflection and changes in metal transfer characteristics are observed. Metallurgical properties of the weld metal are also affected. An investigation was undertaken to study the effect of external magnetic field on the metal transfer characteristics in CO₂ welding. The metallurgical characteristics of the weld metal were also studied. It has been observed that magnetic field imposition affected the droplet transfer rates and droplet transfer times. Dendrite arm spacing of the weld metal was found to decrease with magnetic field. Magnetic field also increased the carbon diffusion rate from the high carbon base metal to the low carbon metal.