Northern Industrial MIG 130, Руководство оператора

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Northern Industrial Welder
Operating Instructions and Parts Manual MIG 130
aiming directly into the weld joint. If
you experience excessive dripping of
the weld puddle, select a lower heat
setting. Also, the weave bead tends
to work better than the stringer.
6.4 Multiple pass welding
Butt Weld Joints
When butt welding
thicker materials, you will need to
prepare the edges of the material to
be joined by grinding a bevel on the
edge of one or both pieces of the
metal being joined. When this is done,
a
V is created between the two
pieces of metal, that will have to be
welded closed. In most cases more
than one pass or bead will need to be
laid into the joint to close the
V .
Laying more than one bead into the
same weld joint is known as a
multiple-pass weld.
The illustrations in following figure
show the sequence for laying multiple
pass beads into a single V butt joint.
NOTE:
WHEN USING SELF-SHIELDING
FLUX-CORE WIRE it is very
important to thoroughly chip and
brush the slag off each completed
weld bead before making another
pass or the next pass will be of poor
quality.
Fillet Weld Joints. Most fillet weld
joints, on metals of moderate to
heavy thickness, will require multiple
pass welds to produce strong joint.
The illustrations in Figure 19 show
the sequence of laying multiple pass
beads into a T fillet joint and a lap
fillet joint.
6.5 Spot welding
There are three methods of spot
welding: Burn-Through, Punch and
Fill, and Lap. Each has advantages
and disadvantages depending on the
specific application as well as
personal preference.
1. The BURN-THROUGH METHOD
welds two overlapped pieces of metal
together by burning through the top
piece and into the bottom piece. With
the burn-through method, larger wire
diameters tend to work better than
smaller diameters. Wire diameters
that tend to work best, with the burn-
through method are 0.035 inch self-
shielding flux-core wire. Do not use
0.030 inch self-shielding flux core
wires when using the burn-through
method unless the metal is VERY thin
or excessive filler metal build-up and