Thermal Dynamics A80 CUTMASTER, Руководство по эксплуатации, Страница: 43 / 130

A80
0-4985 OEPRATION
4T-3
4T.04 Cut Quality
NOTE!
Cut quality depends heavily on setup and
parameters such as torch standoff, align-
ment with the workpiece, cutting speed, gas
pressures, and operator ability.
Cut quality requirements differ depending on application.
For instance, nitride build - up and bevel angle may be major
factors when the surface will be welded after cutting. Dross
- free cutting is important when finish cut quality is desired
to avoid a secondary cleaning operation. The following cut
quality characteristics are illustrated in the following figure:
Kerf Width
Cut Surface
Bevel Angle
Top Edge
Rounding
Cut Surface
Drag Lines
Dross
Build-Up
Top
Spatter
A-00007
Cut Quality Characteristics
Cut Surface
The desired or specified condition (smooth or rough)
of the face of the cut.
Nitride Build - Up
Nitride deposits can be left on the surface of the cut
when nitrogen is present in the plasma gas stream.
These buildups may create difficulties if the material is
to be welded after the cutting process.
Bevel Angle
The angle between the surface of the cut edge and a
plane perpendicular to the surface of the plate. A per-
fectly perpendicular cut would result in a 0° bevel angle.
Top - Edge Rounding
Rounding on the top edge of a cut due to wearing from
the initial contact of the plasma arc on the workpiece.
Bottom Dross Buildup
Molten material which is not blown out of the cut area
and resolidifies on the plate. Excessive dross may re-
quire secondary cleanup operations after cutting.
Kerf Width
The width of the cut (or the width of material removed
during the cut).
Top Spatter (Dross)
Top spatter or dross on the top of the cut caused by
slow travel speed, excess cutting height, or cutting tip
whose orifice has become elongated.
4T.05 General Cutting Information
! !
WARNING
Disconnect primary power at the source
before disassembling the power supply,
torch, or torch leads.
Frequently review the Important Safety
Precautions at the front of this manual. Be
sure the operator is equipped with proper
gloves, clothing, eye and ear protection.
Make sure no part of the operator’s body
comes into contact with the workpiece
while the torch is activated.
!!
CAUTION
Sparks from the cutting process can cause
damage to coated, painted, and other sur-
faces such as glass, plastic and metal.
NOTE!
Handle torch leads with care and protect
them from damage.
Piloting
Piloting is harder on parts life than actual cutting be-
cause the pilot arc is directed from the electrode to the
tip rather than to a workpiece. Whenever possible, avoid
excessive pilot arc time to improve parts life.
Torch Standoff
Improper standoff (the distance between the torch tip
and workpiece) can adversely affect tip life as well as
shield cup life. Standoff may also significantly affect the
bevel angle. Reducing standoff will generally result in
a more square cut.
Edge Starting
For edge starts, hold the torch perpendicular to the
workpiece with the front of the tip near (not touching)
the edge of the workpiece at the point where the cut is
to start. When starting at the edge of the plate, do not
pause at the edge and force the arc to "reach" for the
edge of the metal. Establish the cutting arc as quickly
as possible.