Assembly Instructions

components of air and has a positive effect on the quality of the
welding seam.
5.3 Shielding gases
For laser welding metals, mainly inert (inactive) gases are used.
Inert gases do not react with the base material or only to a very
limited extent.
Recommended shielding gases are:
■
Nitrogen (N
2
)
■
Argon (Ar)
■
Helium (He)
Industrially produced gases always contain a small amount of
impurities. The purity of the gases is indicated by a system of
digits.
1st digit = number of nines of the percentage
2nd digit = last digit of the percentage
Example: He 4.6 = Helium with purity 99.996 % (by volume)
The service life of a gas cylinder can be easily calculated. Weld-
ing gases are supplied in gas cylinders. A gas cylinder contains
in most cases 50 liters of a gas which is under a pressure of
200 bar.
Fig. 2-37
with T: Service life
V: Volume of the gas cylinder
p: Filling pressure
Q: Specific gas consumption
Tab. 2-9
Example:
V = 50 l, p = 200 bar, Q = 40 l/h
→ T = 50 l • 200 bar / 40 l/h = 250 h
22-50-17-CRen
2020-01
Using shielding gas
2‐43
Purity of the gas
Service life of a gas cylinder