The process “Drawn arc stud welding” is used for studs of an approximate diameter of 3 to 25 mm, welding current up to 3.000 A and welding times up to 3.000 ms.
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. If a ceramic ferrules was used, it will be removed afterwords.
