Thermal Arc Viking 210GM, Operating Manual

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Viking 210GM, 250GM
25
Weld metal deposition rate is proportional to current density. Current density is defined as the
current per cross sectional area of the electrode wire and is normally expressed as amps per mm
2
.
An example is tabled below.
Electrode Wire Size
Current (Amps)
Current Density
(Amps/mm
2
)
Deposition Rate
(lbs/hour)
0.9mm (.035”) 200 314 7.0
1.2mm (.045”) 200 177 6.2
Table 9 - 0.9mm (.035”)/1.2mm (.045”) wire deposition rate
This demonstrates that where the upper limit of current is limited by machine capacity and duty
cycle, higher deposition rates and therefore greater productivity will be achieved by using smaller
electrode wire. The Viking is a
particularly efficient MIG
welder with the 0.9mm steel
wire in spray transfer mode.
The savings from decreased
welding time will more than
cover the small cost penalty of
the smaller electrode wire sizes.
(0.9mm (.035”) wire cost
approx. 10% more than 1.2mm
(.045”), but is deposited approx. 15% faster).
Higher current density (or smaller diameter wire) also gives deeper penetration as shown Figure 9.
10.6 Stitch Welding Operation
Stitch welding is normally used to bridge excessive gaps between panels or when welding very
thin material to prevent heat build up and distortion. Set the controls as follows for stitch welding:
a) Coarse & Fine Voltage Selector Switches and Wirespeed Control
Set these controls to obtain the desired welding conditions for the wire and material being
welded.
b) Mode Selector Switch
Set the
MODE SELECTOR switch to STITCH.
c) Spot Time
Adjust the
SPOT TIME control knob for the desired weld or 'ON' time whilst stitch welding.
d) Dwell Time
Adjust the
DWELL TIME control knob for the desired interval or 'OFF' time whilst stitch
welding.
Work Piece
Penetration comparison using the same current (200A) for both electrodes
0.9 mm
1.2 mm
(.035") (.045")
Figure 9 - Wire penetration comparison