MetFab - Welding Fume Handbook - Flipbook - Page 28
9 Effect of shielding gas: ozone
I
0.15
I
0.10
011
0.10
I
0.07
0.05
I
Ozone exposure ppm
0.21
0.20
0
Ferromaxx® 15
70% Ar/20% He/10%CO
Ferromaxx® Plus
92% Ar/8%CO/NO
shielding gas
Figure 18: The effect of shielding gas on exposure to ozone during
MAG welding of mild steel (33% duty cycle) with spray transfer
The mixtures containing helium, particularly Ferromaxx®
Plus, provide higher productivity without any significant
disadvantage in terms of ozone generation.
Figure 19 shows the relationship between exposure to
ozone and arc voltage for an argon/carbon dioxide/oxygen
(Ferromaxx® 15) shielding gas during MAG welding of mild
steel with spray transfer. Exposure increases substantially
with arc voltage.
Average exposure to ozone ppm
0.35
0.30
0.25
0.20
0.15
0.10
0.05
I
27
I
28
I
29
I
30
I
31
I
32
I
33
I
34
Voltage
Figure 19: The effect of voltage on exposure to ozone during MAG welding of mild steel
(33% duty cycle) with spray transfer and Ferromaxx® 15 shielding gas
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