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Recommended Electrode Angles for Fillet Welds
1st Run
40°
40°
40°
40°
3rd Run
20–30°
20–30°
20–30°
20–30°
20–30°
20–30°
20–30°
20–30°
Recommended Electrode Angles for Fillet Welds
Multi-run horizontal fillets have each run made using the same run
lengths (run length per electrode table). Each run is made in the
same direction, and care should be taken with the shape of each, so
that it has equal leg lengths and the contour of the completed fillet
weld
is slightly convex with no hollows in the face.
Vertical fillet welds can be carried out using the upwards or
downwards technique. The characteristics of each are: upwards –
current used is low, penetration is good, surface is slightly convex
and irregular. For multiple run fillets large single pass weaving runs
can be used. Downwards – current used is medium, penetration is
poor, each run is small, concave and smooth (only SolidSTRIKE MSS
E6013 is suitable for this position).
The downwards method should be used for making welds on thin
material only. Electrodes larger than 4.0 mm are not recommended
for vertical down welding. All strength joints in vertical plates 10.0
mm thick or more should be welded using the upward technique.
This method is used because of its good penetration and weld
metal quality. The first run of a vertical up fillet weld should be
a straight sealing run made with 3.15 mm or 4.0 mm diameter
electrode. Subsequent runs for large fillets may be either numerous
straight runs or several wide weaving runs.
Correct selection of electrodes is important for vertical welding.
In overhead fillet welds, careful attention to technique is necessary
to obtain a sound weld of good profile. Medium current is required
for best results. High current will cause undercutting and bad
shape of the weld, while low current will cause slag inclusions. To
produce a weld having good penetration and of good profile, a short
arc length is necessary. Angle of electrode for overhead fillets is
illustrated above.
2nd Run
55–60°
55–60°
55–60°
55–60°
Multi-run Fillet
6
6
6
6
5
5
3
3
5
3
5
3
1
1
2
2
4
4
1
2
4
1
2
4
Recommended Angles for Overhead Fillet Welds
15˚
3.8 Typical Defects Due to Faulty Technique
Shielded metal arc welding, like other welding processes, has
welding procedure problems that may develop which can cause
defects in the weld. Some defects are caused by problems with the
materials. Other welding problems may not be foreseeable and may
require immediate corrective action. A poor welding technique and
improper choice of welding parameters can cause weld defects.
Defects that can occur when using the shielded metal arc welding
process are slag inclusions, wagon tracks, porosity, wormhole
porosity, undercutting, lack of fusion, overlapping, burn through, arc
strikes, craters, and excessive weld spatter. Many of these welding
technique problems weaken the weld and can cause cracking.
Other problems that can occur which can reduce the quality of the
weld are arc blow, finger nailing, and improper electrode coating
moisture contents.
Defects caused by welding technique
Slag Inclusions
Slag inclusions occur when slag particles are trapped inside the
weld metal which produces a weaker weld. These can be caused
by:
• erratic travel speed
• too wide a weaving motion
• slag left on the previous weld pass
• too large an electrode being used
• letting slag run ahead of the arc.
MIG 250GS Operating manual
45˚
30˚
021
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