Study on the arc behaviors under the condition of argon and helium supply alternately

In this paper, a solenoid valve control system was used to supply argon and helium alternately to the welding torch, under the frequency of 1 Hz and 4 Hz. The radial distribution of arc pressure was measured by the water-cooled copper plate with holes, and the arc shape was recorded by high-speed photography. The results indicated the arc produced an obvious effect of pulsed pressure, due to the argon-arc and helium-arc stroked in turn in the process of argon and helium supply alternately at 1 Hz frequency. It produced a strong impact and stirring effect on the metal of molten pool, leading to the improvement of weld penetration and width, and the weld surface presented the typical distribution pattern of fish scale.