Arc initiation method of tungsten argon arc welding
1. Contact short circuit arc starting method
It is not possible to short-circuit the tungsten electrode directly in contact with the welding part, because the tungsten in the extreme part will pollute the molten pool and form tungsten clip. Usually can use arc plate or set copper skin, carbon block near the welding joint, in these arc plate with contact short-circuit method arc, and then move the arc to the welding site. The disadvantage of this arc starting method is that the tungsten electrode loss is large when the arc starting, the shape of the tungsten extreme part is easy to be destroyed, and it is only used when the welding machine does not have high frequency arc starting device.
2. High frequency and high pressure arc starting method
The gap between the tungsten electrode and the welder (2 ~ 5mm) is broken down by the high frequency high voltage produced by the high frequency oscillator installed in the welder control box to ignite the arc.
3. High voltage pulse arc starting method
A high voltage pulse is added between the tungsten electrode and the weldment to ionize the gas medium between the two electrode and initiate an arc.
