Tweco 1000 CE Merlin - Manuel (Page 41)

Manual 0-2731 4-7 OPERATION
Kerf Width
The width of material removed during the cut.
Nitride Build-up
Nitride deposits which may remain on the cut edge of the
carbon steel when nitrogen is present in the plasma gas
stream. Nitride buildups may create difficulties if the steel
is welded after the cutting process.
Kerf Width
Cut Surface
Bevel Angle
Top Edge
Rounding
Cut Surface
Drag Lines
Dross
Build-Up
Top
Spatter
A-00007
Figure 4-7 Cut Quality Characteristics
Cut quality will vary on different types of and material thick-
nesses. The following table shows the cut quality that can be
expected from this equipment for materials with a thickness
from gage to 1/2 inch (12.7 mm):
Description of Cut Characteristics
Excellent - Minimum bevel (0 - 4°), minimum kerf (2 x tip orifice
diameter), little or no dross, smooth cut surface.
Good - Slight bevel (0 - 10°), slightly wider kerf (2-1/2 x tip orifice
diameter), some dross (easily removed), medium-
smooth cut surface, slight top edge rounding.
NR - Excessive bevel (over 10°), wide kerf (over 2-1/2 x tip
orifice diameter), medium to heavy dross, rough cut
surface, top edge rounding.
NOTES
Cut quality depends heavily on set-up and param-
eters such as torch standoff, alignment with the
workpiece, cutting speed, gas pressures, and op-
erator ability.
Table 4-A Cut Quality on Various Materials
Type of Material
Type of Gases Material Thickness Carbon Steel Stainless Aluminum
Gage Excellent Good - Excellent Good - Excellent
Air Plasma and
Air Secondary
Gage to 1 inch Excellent Good Good
1 to 1-1/2 inches Excellent Good Good
Gage NR Good - Excellent Good - Excellent
Nitrogen Plasma and
Air or CO2 Secondary
Gage to 1/2 inch NR Good - Excellent Good - Excellent
1/2 to 1 inch NR Good - Excellent Good - Excellent
Gage to 1/4 inch NR Good Good
Nitrogen Plasma and
Water Secondary
1/4 to 1/2 inch NR Excellent Good - Excellent
1/2 to 1-1/2 inches NR NR NR
Gage to 1/4 inch NR NR NR
Ar/H2 Plasma and
N2 or CO2 Secondary
1/4 to 1/2 inch NR Good Excellent
1/2 to 1 inch NR Good Good
Oxygen Plasma and
Air Secondary
Gage to 1 inch Excellent NR NR
Oxygen Plasma and
Oxygen Secondary
Gage to 1/4 inch Excellent NR NR