WELDTECH WT200MP, Руководство по эксплуатации

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WT200MP Welding Machine
www.weldtech.net.nz
ing (pushing). Whether the operator is left handed
or right handed has to be considered to realize the
effects of each angle in relation to the direction of
travel.
Nozzle Angle, Right Handed Operator
(Fig 1-10)
Direction of Travel
Leading or “Pushing”
Angle (Forward Pointing)
Trailing or “Pulling”
Angle (Backward Pointing)
90 o
Establishing the Arc and Making Weld Beads
Before attempting to weld on a finished piece of
work, it is recommended that practice welds be
made on a sample metal of the same material as that
of the finished piece.
The easiest welding procedure for the beginner to
experiment with MIG welding is the flat position. The
equipment is capable of flat, vertical and overhead
positions.
For practicing MIG welding, secure some pieces of 16
or 18 gauge (1.5mm or 2.0mm) mild steel plate (150
x 150mm). Use (0.8mm) flux cored gasless wire or a
solid wire with shielding gas.
Setting of the Power Source
Power source and Current (Wire Speed) setting re-
quires some practice by the operator, as the welding
plant has two control settings that have to balance.
These are the Current (Wire Speed) control and the
welding Voltage Control.
The welding current is determined by the Current
(Wire Speed) control, the current will increase with
increased Current (Wire Speed), resulting in a shorter
arc. Less Current (Wire Speed) will reduce the current
and lengthen the arc. Increasing the welding voltage
hardly alters the current level, but lengthens the arc.
By decreasing the voltage, a shorter arc is obtained
with a little change in current level.
When changing to a different electrode wire dia
eter, different control settings are required. A thinner
electrode wire needs more Current (Wire Speed) to
achieve the same current level.
A satisfactory weld cannot be obtained if the Current
(Wire Speed) and Voltage settings are not adjusted to
suit the electrode wire diameter and the dimensions
of the work piece.
If the Current (Wire Speed) is too high for the weld-
ing voltage, “stubbing” will occur as the wire dips into
the molten pool and does not melt. Welding in these
conditions normally produces a poor weld due to
lack of fusion. If, however, the welding voltage is too
high, large drops will form on the end of the wire,
causing spatter. The correct setting of voltage and
Current (Wire Speed) can be seen in the shape of
the weld deposit and heard by a smooth regular arc
sound.
Electrode Wire Size Selection
The choice of Electrode wire size and shielding gas
used depends on the following:
• Thickness of the metal to be welded
• Type of joint
• Capacity of the wire feed unit and power source
• The amount of penetration required
• The deposition rate required
• The bead profile desired
• The position of welding
• Cost of the wire