摘要
The interference of the A C. Plasma arc with the D C. pilot arc in the conventional A. C. PAW was investigated in this paper. The results of the investigation show that the directions of both electric field and current of plasma main arc are opposite to those of pilot arc during the time of DCEP is the reason of the arc interference, which can cause the neutralization of the charges adjacent to the surfaces of the tungsten tip and the nozzle and make either the plasma arc or the pilot arc unstable. The unsuitable potential of the nozzle to the electric field of the plasma arc is the common reason of both the arc interference and the double arc. By using the discontinuous pilot arc presented in the paper. not only the arc interference can be avoided. but also the reverse plasma arc can be reliably erignited and the output current of the pilot arc power source can be to some extent used to heat the tvorkpiece.
The interference of the A C. Plasma arc with the D C. pilot arc in the conventional A. C. PAW was investigated in this paper. The results of the investigation show that the directions of both electric field and current of plasma main arc are opposite to those of pilot arc during the time of DCEP is the reason of the arc interference, which can cause the neutralization of the charges adjacent to the surfaces of the tungsten tip and the nozzle and make either the plasma arc or the pilot arc unstable. The unsuitable potential of the nozzle to the electric field of the plasma arc is the common reason of both the arc interference and the double arc. By using the discontinuous pilot arc presented in the paper. not only the arc interference can be avoided. but also the reverse plasma arc can be reliably erignited and the output current of the pilot arc power source can be to some extent used to heat the tvorkpiece.
