Study of the Effect of Shielding Gas on the Plasma Flow of an Electric Arc and on the Droplet of a Molten Metal

Abstract The effect of a shielding gas on the plasma flow of an electric arc and molten metal is studied. The effect of the shielding gas on the plasma flow of the electric arc of molten metal is simulated, and a mathematical model is developed that describes the flow of the plasma-forming gas inside a device that forms the necessary directions of plasma flows to form a droplet of molten electrode metal of the required size. It is established that the shielding gas and its pressure affect the gas outflow rate and the formation and size of an electrode metal drop. The time of the formation and detachment of the droplet changes at the increase in the pressure of the shielding gas, the higher the gas pressure, the smaller the volume of the droplet. Argon and carbon dioxide have different effects on the plasma flow of the electric arc, the length of the arc, the formation and detachment of the droplet. The process of the droplet formation can be controlled by changing the gas composition, pressure, and gas velocity. It is determined that the gas flow rate increases from 1.2 to 5.2 m/s and the volume of a droplet of molten electrode metal decreases at the increase in the gas flow from 10 to 30 L/min. The droplet volume can be changed on average by 65% depending on the shielding gas.