Smootharc 180 Multiprocess, Руководство по эксплуатации

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size. The following table gives the recommended maximum size of
electrodes that may be used for various thicknesses of section.
Recommended Electrode Sizes
Average Thickness of Plate or Section Max. Recommended Electrode Dia.
≤1.5 mm 2.0 mm
1.5–2.0 mm 2.5 mm
2.0–5.0 mm 3.15 mm
5.0–8.0 mm 4.0 mm
≤8.0 mm 5.0 mm
Welding Current
Correct current selection for a particular job is an important factor in arc
welding. With the current set too low, difficulty is experienced in striking
and maintaining a stable arc. The electrode tends to stick to the work,
penetration is poor and beads with a distinct rounded profile will be
deposited.
Excessive current is accompanied by overheating of the electrode. It will
cause undercut, burning through of the material, and give excessive
spatter. Normal current for a particular job may be considered as the
maximum which can be used without burning through the work, over-
heating the electrode or producing a rough spattered surface, i.e. the
current in the middle of the range specified on the electrode package is
considered to be the optimum.
In the case of welding machines with separate terminals for different
size electrodes, ensure that the welding lead is connected to the correct
terminal for the size electrode being used. When using machines with
adjustable current, set on the current range specified.
The limits of this range should not normally be exceeded.
The following table shows the current ranges generally recommended
for BOC Smootharc 13.
Generally Recommended Current Range for BOC Smootharc 13
Size of Electrode (mm) Current Range (Amp)
2.5 60–95
3.2 110–130
4.0 140–165
5.0 170–260
Arc Length
To start the arc, the electrode should be gently scraped on the work until
the arc is established. There is a simple rule for the proper arc length; it
should be the shortest arc that gives a good surface to the weld. An arc
too long reduces penetration, produces spatter and gives a rough surface
finish to the weld. An excessively short arc will cause sticking of the
electrode and rough deposits that are associated with slag inclusions.
For downhand welding, it will be found that an arc length not greater
than the diameter of the core wire will be most satisfactory. Overhead
welding requires a very short arc, so that a minimum of metal will be
lost. Certain BOC electrodes have been specially designed for ‘touch’
welding. These electrodes may be dragged along the work and a
perfectly sound weld is produced.
Electrode Angle
The angle which the electrode makes with the work is important to
ensure a smooth, even transfer of metal. The recommended angles
for use in the various welding positions are covered later.
27 BOC Smootharc 180 Multiprocess operating manual