CAUTION!
►
Please note that the torch must always be put down on an insulated
surface after welding.
♦
Always switch off the welder after completing welding work and
during breaks and pull the plug out of the mains socket.
Weld types
Forehand welding
The torch is pushed forwards.
Result: lower penetration depth, broader weld, flatter weld bead and
greater fusion error tolerance.
Backhand welding
The torch is dragged from the weld joint.
Result: higher penetration depth, narrower weld, higher weld bead and
lower fusion error tolerance.
Welded joints
There are two basic types of joint types in welding: Butt welds and angle
welding (outer edge, inner edge and overlapping).
Butt welds
With butt welds of up to 2 mm, the weld edges are moved completely
together.
For greater thicknesses, see the table below:
d
S
S=
1–3 mm
Area d=
0.5–1.5 mm
Fusion face
1–2 mm
d=
Vertical
1–1.5 mm
d=
│
GB │ IE
■
28
3–4 mm
4–6 mm
1.5–2.5 mm
2–3 mm
2–3 mm
3–4 mm
1.5–2.5 mm
2–3 mm
Flat butt welds
Welds should be made without interruption and with a sufficient penetra-
tion depth. Therefore, good preparation is extremely important.
■
The factors that influence the quality of the weld result are: the amper-
age, the distance between weld edges, the inclination of the torch and
the corresponding diameter of the welding wire.
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The steeper you hold the torch against the workpiece, the higher the
penetration depth and vice versa.
■
To forestall or reduce deformations that can happen during the material
hardening process, it is good to fix the workpiece, where possible,
using a clamp that counteracts the contraction and deformation of the
material.
■
Avoid stiffening the welded structure to prevent cracks in the weld.
These problems can be avoided if there is a possibility of turning the
workpiece so that the weld can be carried out in two passes running in
opposite directions.
Welds on an outer edge
The preparation for this is very simple.
For thicker materials, however, it is no longer expedient. In this case, it is
better to prepare a joint as shown opposite in which the edge of a plate is
angled.
45°
PFDS 33 A1