HBS 93-10-0702A, Operating Manual, Page: 26 / 78

26 ARC 800 Order No. BA 93-10-0702A Issue 01.03.08
5.2 Functional Principle of Stud Welding
The face of a stud-shaped welding element and the opposite surface of the workpiece
are molten by an arc. Stud welding is suitable for the welding of joining elements across
the entire cross-section, mainly using pin-shaped metallic welding elements with
metallic workpieces.
The various processes of arc stud welding are distinguished by:
– The method of weld pool protection (shielding gas - SG, ceramic ferrule - CF or no
protection - NP)
– The length of welding time (standard ARC or short-cycle drawn-arc stud welding - SC)
– The energy source (welding rectifier supplied by mains, inverter, capacitor battery)
Variations for drawn-arc ignition are described in current standards and regulations (see
appendix).
Drawn-Arc Stud Welding
The HBS stud welding unit operates by process of ‘arc stud welding with drawn-arc
ignition’ according to the current standards (see appendix). The standards assign this
method of joining pin-shaped elements with plane workpieces to the so called ‘Arc
Pressure Welding’ (code BH).
Joining is carried out in plastic or liquefied condition of the welding zone. The process
can be carried out mechanically or automatically, depending on the used welding guns/
welding heads.
Generally, the positive pole of the power unit is connected to the workpiece. The welding
element is manually or automatically inserted into the chuck of the welding gun or of the
welding head. Then it is placed onto the workpiece - possibly equipped with a ceramic
ferrule (see position 1). When the button of the welding gun is triggered, the automated
welding process starts, which works as follows:
Pre-flow of shielding gas depending on set pre-flow time (only with shielding gas for weld
pool protection).