Instructions / Assembly

9
GMAW
www.lincolnelectric.com
Axial Spray Transfer
K
eywords:
Globular to Axial Spray Transition Current
Weld Interface
Axial spray metal transfer is the higher energy mode of metal
transfer, whereby a continuously fed solid or metal-cored wire
electrode is deposited at a higher energy level, resulting in a
stream of small molten droplets. The droplets are propelled
axially across the arc.
Axial spray transfer is the higher energy form of GMAW metal
transfer. To achieve axial spray transfer, binary blends containing
argon + 1-5 % oxygen or argon + CO
2
, where the CO
2
levels
are 18% or less. Axial spray transfer is supported by either the
use of solid wire or metal-cored electrodes. Axial spray transfer
may be used with all of the common alloys including: aluminum,
magnesium, carbon steel, stainless steel, nickel alloys, and
copper alloys.
For most of the diameters of filler metal alloys, the change to
axial spray transfer takes place at the globular to spray transition
current. A stream of fine metal droplets that travel axially from
the end of the electrode characterizes the axial spray mode of
metal transfer. The high puddle fluidity restricts its use to the
horizontal and flat welding positions.
For carbon steel, axial spray transfer is applied to heavier section
thickness material for fillets and for use in groove type weld
joints. The use of argon shielding gas compositions of 95%, with
a balance of oxygen, creates a deep finger-like penetration
profile, while shielding gas mixes that contain more than 10%
CO
2
reduce the finger-like penetration profile and provide a
more rounded type of penetration.
The selection of axial spray metal transfer is dependent upon the
thickness of base material and the ability to position the weld
joint into the horizontal or flat welding positions. Finished weld
bead appearance is excellent, and operator appeal is very high.
Axial spray transfer provides its best results when the weld joint
is free of oil, dirt, rust, and millscale.
Advantages of Axial Spray Transfer
•
High deposition rates.
•
High electrode efficiency of 98% or more.
• Employs a wide range of filler metal types in an equally wide
range of electrode diameters.
• Excellent weld bead appearance.
TABLE 1 — Transition Currents for Axial Spray Transfer
Electrode Approximate
Filler Metal Diameter Shielding Current
Type Inches (mm) Gas (Amps)
0.030 (0.8) 90% Argon, 10% CO
2
155 - 165
0.035 (0.9) 90% Argon, 10% CO
2
175 - 185
0.045 (1.2) 90% Argon, 10% CO
2
215 - 225
0.052 (1.3) 90% Argon, 10% CO
2
265 - 275
Carbon and 0.062 (1.6) 90% Argon, 10% CO
2
280 - 290
Low Alloy
Solid Steel 0.035 (0.9) 98% Argon, 2% O
2
130 - 140
0.045 (1.2) 98% Argon, 2% O
2
205 - 215
0.052 (1.3) 98% Argon, 2% O
2
240 - 250
0.062 (1.6) 98% Argon, 2% O
2
265 - 275
Carbon and 0.040 (1.0) 90% Argon, 10% CO
2
140 - 150
Low Alloy 0.045 (1.2) 90% Argon, 10% CO
2
160 - 170
Composite 0.052 (1.3) 90% Argon, 10% CO
2
170 - 180
Steel
0.062 (1.6) 90% Argon, 10% CO
2
220 - 230
0.030 (0.8)
98% Argon, 2% O
2
120 - 130
0.035 (0.9) 98% Argon, 2% O
2
140 - 150
0.045 (1.2) 98% Argon, 2% O
2
185 - 195
Stainless 0.062 (1.6) 98% Argon, 2% O
2
250 - 260
Steel
0.030 (0.8)
98% Argon, 2% CO
2
130 - 140
0.035 (0.9) 98% Argon, 2% CO
2
200 - 210
0.045 (1.2) 98% Argon, 2% CO
2
145 - 155
0.062 (1.6)
98% Argon, 2% CO
2
255 - 265
GMAW
Axial Spray Transition Currents for Solid and Composite
Carbon Steel Electrodes and Stainless Steel Solid Wire Electrodes
FIGURE 4: Axial Spray Weld Metal Transfer Characteristics
•
High operator appeal and ease of use.
• Requires little post weld cleanup.
• Absence of weld spatter.
• Excellent weld fusion.
• Lends itself to semiautomatic, robotic, and hard automation
a
pplications.
L
imitations of Axial Spray Transfer
•
Restricted to the flat and horizontal welding positions.
• Welding fume generation is higher.
•
The higher-radiated heat and the generation of a very bright
arc require extra welder and bystander protection.
• The use of axial spray transfer outdoors requires the use of a
w
indscreen(s).
• The shielding used to support axial spray transfer costs more
than 100% CO
2
.