Low-temperature plasma generator with direct arc for plasma remelting

An efficient low-temperature plasma generator with direct arc for plasma remelting was developed and studied with direct and reverse polarity. It has an expanding nozzle channel and the remelted metal acts as a second electrode. An efficiency of $\approx90\%$ and a long service life with a current strength of up to $200$ A were obtained. It is shown that the nozzle increases arc stability at an opening angle of $12^{\circ}$. It is established that a super-equilibrium nitrogen content $($up to $0.22\%)$ in the molten metal can be obtained.