Drawn-arc stud welding with shielding gas
Details of our welding technology
The process „drawn arc stud welding with shielding gas“ is used for welding studs of a diameter of 3 to 12 mm ( 16mm).
In general, the positive pole of the power-source is connected to the workpiece.
The stud will be inserted into the chuck of the stud welding gun and positioned onto the workpiece, possibly by adding a ceramic ferrule.
Initiating the welding process: by means of a lifting mechanism, the stud will be lifted and at first an auxiliary arc (pilot arc) of a low current will be drawn. Then the main arc will be drawn between the tip of the stud and the workpiece.
The main arc of a high amperage must be adjusted to the diameter of the stud.
The cross sectional area of the stud and the opposite workpiece a partially melting.
After the lapse of the adjusted welding time, the stud is moved towards the work piece and both melting zones join tightly.
The power-source turns off, the melting zone solidifies and cools down.
In order to obtain a good gas-protection, an adequate appliance is indispensable. At the upper part of the chuck, the gas chamber should be sealed by means of a rubber sleeve.
Down at the workpiece, lateral slotts are required to allow the gas to escape.
The use of appropriate shielding gas is of great importance: mild steel and stainless steel: 82% Ar and 18% Co2, for aluminium; pure Argon or Ar and He.
| Process | Stud welding with shielding gas |
|---|---|
| Minimum sheet thickness t | 1/8 d |
| Maximum stud diameter d for welding from different positions | 12(16) ↓ 6 ← 8 ↑ |
| Suitable surface conditions¹) | bright metal, rolling skin, primer suitable for welding, surface rust, thin layer of oil, zinc coating |
Unsuitable surface conditions¹) |
loose layers of scaling, heavily corroded, protective coating |
| Common applications | studs from M 6 to M 12 in downhand position, especially with automatic feeding of studs |
¹) Here, we can give only general hints without any commitment or warranty on our part. The conditions must be tested in each individual case. Basically, a higher degree of surface cleanliness is required for shorter welding times. The best results are always achieved on bright metal surfaces.
