ESAB ET 220i AC/DC, Руководство по эксплуатации

Страница: 51 / 74

ET 220I AC/DC
Manual 0-5346 BASIC WELDING GUIDE
4-5
Art # A-07698
Figure 4-12: Weld Build up Sequence
Heavy plate will require several runs to complete the joint.
After completing the first run, chip the slag out and clean the
weld with a wire brush. It is important to do this to prevent
slag being trapped by the second run. Subsequent runs are
then deposited using either a weave technique or single beads
laid down in the sequence shown in Figure 4-12. The width
of weave should not be more than three times the core wire
diameter of the electrode. When the joint is completely filled,
the back is either machined, ground or gouged out to remove
slag which may be trapped in the root, and to prepare a suit-
able joint for depositing the backing run. If a backing bar is
used, it is not usually necessary to remove this, since it serves
a similar purpose to the backing run in securing proper fusion
at the root of the weld.
B. Fillet Welds
These are welds of approximately triangular cross-section
made by depositing metal in the corner of two faces meeting
at right angles. Refer to Figure 4-4.
A piece of angle iron is a suitable specimen with which to
begin, or two lengths of strip steel may be tacked together at
right angles. Using a 1/8" electrode, position angle iron with
one leg horizontal and the other vertical. This is known as a
horizontal-vertical (HV) fillet. Strike the arc and immediately
bring the electrode to a position perpendicular to the line of the
fillet and about 45º from the vertical. Some electrodes require
to be sloped about 20º away from the perpendicular position to
prevent slag from running ahead of the weld. Refer to Figure
4-13. Do not attempt to build up much larger than 1/4" width
with a 1/8" electrode, otherwise the weld metal tends to sag
towards the base, and undercut forms on the vertical leg.
Multi-runs can be made as shown in Figure 4-14. Weaving in
HV fillet welds is undesirable.
Art # A-07699_AB
45° from
vertical
60° - 70° from line
of weld
Figure 4-13: Electrode Position for HV Fillet Weld
Art # A-07700_AB
1
2
3
4
5
6
Figure 4-14: Multi-runs in HV Fillet Weld
C. Vertical Welds
1. Vertical Up
Tack weld a three feet length of angle iron to your work
bench in an upright position. Use a 1/8" electrode. Make
yourself comfortable on a seat in front of the job and
strike the arc in the corner of the fillet. The electrode
needs to be about 10º from the horizontal to enable a
good bead to be deposited. Refer Figure 4-15. Use a
short arc, and do not attempt to weave on the first run.
When the first run has been completed de-slag the
weld deposit and begin the second run at the bottom.
This time a slight weaving motion is necessary to cover
the first run and obtain good fusion at the edges. At the
completion of each side motion, pause for a moment to
allow weld metal to build up at the edges, otherwise un-
dercut will form and too much metal will accumulate in
the centre of the weld. Figure 4-16 illustrates multi-run
technique and Figure 4-17 shows the effects of pausing
at the edge of weave and of weaving too rapidly.
Art # A-07701
Figure 4-15: Single Run Vertical Fillet Weld