EFFECTIVE POWER OF THE REVERSE POLARITY WELDING ARC WHEN SURFACING ALUMINUM WITH A CONSUMABLE ELECTRODE

The paper analyzes the information about the effective power of a reverse polarity arc on an aluminum part and the influence of the arc cathode region on it. The study differentiated the effective power of the direct polarity arc into its main components. The authors carried out the experiments to measure the effective power of the reverse polarity arc for aluminum welding. To determine the effective power, the calorimetry was used when hardfacing a wire of 1.2 mm diameter on the Al-Mn alloy plate and the deposited metal then was weighed. Based on the experiment results, the authors calculated an average algebraic deviation of αН∙I hardfacing performance and effective power. As a result, the authors proposed the procedure to determine the electrode wire fusion coefficient at zero stick-out α₀ according to its dependence on the arc current, which increases at electrode diameter decreasing. This coefficient is about 25 % less than that of steel. By assuming a weak dependence of anode power on the arc current, this fact proves the obtained data on the high heat content of electrode metal droplets of an aluminum wire in comparison with a steel wire. At the droplet transfer of electrode metal, the cathode region power of the arc makes the prevailing contribution to the total effective power of the reverse polarity arc. At the current density equal to 175 А/mm², the specific effective power of the cathode region action is q_SC=9.0 W/А, the power of the electrode metal is q_E=4.6 W/А, and the plasma flow power is q_P=5.2 W/А.

effective power, hardfacing, aluminum, reverse polarity, calorimetry, consumable electrode, fusion coefficient, aluminum wire, droplets heat content