MetFab - Welding Fume Handbook - Flipbook - Page 24
8 Effect of shielding gas: particulate fume
TIG
Shielding gases for TIG welding stainless steel are usually
pure argon, pure helium, argon/helium mixtures or argon
with small additions of hydrogen or nitric oxide. The last two
types are formulated especially to reduce ozone generation,
and this aspect is discussed below.
Shielding gas composition does affect fume emission rate, as
Figure 14 shows, but the amounts of fume generated are so
small as to make emission rate data insignificant.
0.13
0.12
I
0.09
I
0.06
I
0.03
I
Fume emission rate mg/s
I
0.15
0.08
0.09
0.09
0.07
0
Argon
Alumaxx® Plus
25% Ar/75% He
96% Ar/2% H
95% Ar/5% H
shielding gas
Figure 14: The effect of shielding gas on fume emission rate
during TIG welding of austenitic stainless steel
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