HBS 93-10-0702A, Operating Manual, Page: 28 / 78

28 ARC 800 Order No. BA 93-10-0702A Issue 01.03.08
5.2.1 Drawn-Arc stud Welding with Ceramic Ferrule
Drawn-arc stud welding with ceramic ferrule is used with welding elements of 3 to 25 mm
diameter (preferably above 12 mm diameter) and with welding times of 50 to 2000 ms.
It is generally suitable for all welding positions. When stud welding with ceramic ferrule,
the welding position is PA (vertical). The major part of all applications applies to this
procedure.
The ceramic ferrule (CF)
– prevents atmosphere from getting to the weld pool by a formation of metal vapor in
the arc chamber
– stabilizes and concentrates the arc, thus decreasing the arc blow effect
– forms the melt under pressure to a weld collar and supports the weld pool on a vertical
wall and overhead
– protects the welder from arc radiation and welding spatters
Normally, the ceramic ferrule is used for only one weld and is removed after solidification
of the weld pool.
Standard welding elements and ceramic ferrules are described in several standards (see
appendix). When using concrete anchors or shear connectors the front area can be
plane constructed with a small pressed-in aluminum ball.
Studs with cone-shaped front area and aluminum ball are preferably used with
ceramic ferrule.
5.2.2 Drawn-Arc Stud Welding with Shielding Gas
Drawn-arc stud welding with shielding gas is used with welding elements for a diameter
range of 3 to 12 (16) mm and with welding times from 50 to 2000 ms. Principally, it is
suitable for all welding positions, however, it is preferably used in vertical position PA.
With stud welding with shielding gas, the weld area is protected by shielding gas. The
shielding gas, which is fed from outside through a gas control and an additional device,
displaces the ambient atmosphere from the welding area and reduces considerably pore
formation.
With steel and CrNi steel, the gas mixture 82% Ar and 18% CO
2
(DIN EN ISO 14175 – M21) is mainly used.
With aluminum, pure argon Ar 99,99 (DIN EN ISO 14175 – I1) or
Ar-He mixtures (DIN EN ISO 14175 – I3) are used.