HBS 93-66-1202, Руководство по эксплуатации, Страница: 29 / 76

IT 1002 Order No. BA 93-66-1202 Issue 01.06.08 29
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.
The shielding gas influences
– the arc and the melting behavior of welding element and workpiece,
– the development of the weld collar and the penetration shape via the surface tension.
With stud welding with shielding gas, the shape of the weld collar is not reproducible,
as the shielding gas has no forming effects on the melt – different from a ceramic
ferrule. And so an additional ceramic ferrule may be used in special cases.
The standard welding elements and ceramic ferrules for drawn-arc stud welding are
described in several standards (see appendix). Welding elements with cone-shaped
front area and without an aluminum ball are preferably used.
Studs with cone-shaped front area preferably used under shielding gas.
With shielding gas, you should only weld in position PA (verti-
cal) because due to gravity, the shielding gas cannot prevent
flow of the molten metal.