Anode jet generation conditions affected by the radial current density distribution for maintaining current continuity

To perform high-quality welding, the heat input from the arc to the base metal is controlled. However, an anode jet sometimes occurs. In such cases, control is difficult and weld defects occur. This study elucidates how anode jet generation is affected by the radial current density distribution for maintaining the current continuity. The anode jet starts to occur at 15–20 mm of interelectrode distance. The arc temperature decreases because the arc radius increases. Then electrical conductivity decreases sharply depending on the temperature. If electrical conductivity decreases, then the current density decreases, and the arc cannot maintain the current continuity. When the mean current density is 8.7 × 105 A/m2, the flow velocity is zero at 15 mm. Therefore, this minimum value of the mean current density is the anode jet generation condition.