Voltage And Cut Quality - ESAB B Series Installation, Operation And Maintenance Manual

SECTION 5
Standoff

5.2 VOLTAGE AND CUT QUALITY.

Standoff (arc voltage) has a direct influence on cut quality
and squareness. It is recommended that prior to cutting,
all cutting parameters are set to the manufacturer's sug-
gested conditions. A sample cut should be made fol-
lowed by a close examination of the part.
End View
Cut Face
Arc Voltage
Figure 5-2. Cut Quality
Arc Voltage
(+) Cut Angle
Figure 5-3. Cut Quality (Arc Voltage Too High)
72
ARC VOLTAGE/STANDOFF
Standoff and arc voltage are proportional.
The higher the torch above the plate
(standoff), the higher the operating voltage
and vice versa.
LAG LINES
These lines appear on the cut surface.
They are used to determine if your
process parameters are correct.
If it has an excessive bevel or rounded top edge, it may be
the standoff (arc voltage) is set too high (Figure 5-3).
Lower the voltage until the excessive bevel or rounded
top edge disappears. On material thickness 1/4 inch (6
mm) and greater, a standoff too close may result in a
negative cut angle (Figure 5-5).
ARC VOLTAGE TOO HIGH
Correct Cutting Speed
Positive Cut Angle
Rounded Top Edge
More Dross
Top Dross
Cut Face Smooth
"S" Shaped Lag Lines
CUTTING QUALITY