Tweco 180 Portable MIG - Manual (Page 50)

FABRICATOR 140, 180 OPERATION
Manual 0-4991 4-14 July 20, 2007
4.15 Gas Selection for Gas Metal Arc Welding
Metal Type
Base Plate
Thickness
Filler
Metal
Transfer
Mode
Suggested
Shielding Gas
Welding
Positions
Comments
Greater than
22 gauge
(.030”)
ER70S-X Short
Circuit
100% CO
2
All Position
Welding
High welding speeds. Good
penetration and pool control.
Greater than
22 gauge
(.030”)
ER70S-X Short
Circuit
75% Argon
25% CO
2
All Position
Welding
Suitable for high-current and high-
speed welding.
Greater than
22 gauge
(.030”)
ER70S-X Short
Circuit
92% Argon
8% CO
2
All Position
Welding
Higher deposition rates without melt-
through. Minimum distortion and
spatter. Good pool control for out-of-
position welding.
Carbon
Steel
Greater than
10 gauge ( 1/8”)
ER70S-X Spray
Transfer
92% Argon
8% CO
2
Flat & HV
Fillet
Good arc stability, weld soundness,
and increasing width of fusion.
Greater than
22 gauge
(.030”)
See Note 1 Short
Circuit
Globular
75% Argon
25% CO
2
All Position
Welding
High welding speeds. Good
penetration and pool control.
Applicable for out-of-position welds.
Suitable for high-current and high-
speed welding.
Greater than
22 gauge
(.030”)
See Note 1 Short
Circuit
92% Argon
8% CO
2
All Position
Welding
Good coalescence and bead contour.
Good mechanical properties.
Greater than
3/32”
See Note 1 Spray
transfer
92% Argon
8% CO
2
Flat & HV
Fillet
Reduces undercutting. Higher
deposition rates and improved bead
wetting. Deep penetration and good
mechanical properties.
Low Alloy
and
High Alloy
Steel
Greater than
14 gauge
(.075”)
See Note 1 Short
Circuit
98% Argon
2% CO
2
All Position
Welding
Good control of melt-through and
distortion. Used also for spray arc
welding. Pool fluidity sometimes
sluggish depending on the base alloy.
Greater than
22 gauge
(.030”)
ER308-X
ER309-X
ER316-X Short
Circuit
90% Helium
7.5% Argon
2.5% CO
2
or
81% Argon
18% Helium
1 % CO
2
All Position
Welding
Low CO
2
percentages in Helium mix
minimizes carbon pickup, which can
cause intergranular corrosion with
some alloys. Helium improves wetting
action and contour. CO
2
percentages
above 5% should be used with caution
on some alloys.
Stainless
Steel
Greater than
3/32”
ER308-X
ER309-X
ER316-X Spray
Transfer
90% Helium
7.5% Argon
2.5% CO
2
or
81% Argon
18% Helium
1 % CO
2
Flat & HV
Fillet
Good arc stability. Produces a fluid
but controllable weld pool, good
coalescence, and bead contour.
Minimizes undercutting on heavier
thickness.
Aluminum Greater than
18 gauge
(.045”)
ER4043
ER5356 Spray
Transfer
Argon All Position
Welding
Excellent cleaning action. Provides
more stable arc than helium-rich
mixtures.
Note 1: Contact your Filler Metal Supplier for recommended filler metal for the base metal to be welded.