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3-7. How Manual Pulsed MIG Waveform Components Affect Arc and Burn-off Rate
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Reference Waveform
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Increase Peak Amperage Only
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Decrease Peak Amperage Only
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Increase Background Amperage Only
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Decrease Background Amperage Only
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Increase Pulse Width (TIme) Only
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Decrease Pulse Width (Time) Only
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Increase Pulses Per Second Only
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Decrease Pulses Per Second Only
OM-2805 Page 16
Changes to Arc
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Comments
A Electrode extension (stickout)
B Arc length
C Contact tube-to-work distance should be 3/8 in. to
3/4 in. Recommended gun angle is 10 to 20 de-
grees from vertical.
Increasing peak amperage only:
Increases burn-off rate, which directly affects
arc length
Increases average amperage slightly
Increase heat input slightly
.
Note: A good fine tuning parameter for arc length.
Assuming a constant pulse width (peak time), peak
amperage should be high enough to achieve a spray
transfer. Too low of a peak current often results in a
globular transfer. High peak amperages result in
smaller droplets, and a more forceful or driving arc.
Increasing background amperage only:
Increases arc length
Increases average amperage
Increases heat input and penetration
Increases puddle fluidity
.
This current level is largely responsible for arc stabi-
lization, and must be high enough to maintain the arc
between peak current pulses.
Increasing pulse width (time) only:
Increases arc length
Increases heat input and penetration
Increases arc cone width
Increase average amperage
Increasing pulses per second only:
Increase arc length
Increases average amperage
Increases heat input
Note: A good fine tuning parameter for arc length.
Typically this variable is adjusted to control the Burn off
rate of the wire as it is fed into the arc.
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