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. Too high current is accompanied by overheating of the electrode
resulting undercut and burning through of the base metal and producing 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.
The table shows current ranges generally recommended for a general purpose type 6013
electrode.
Welding Current (Amperage)
Electrode Size ø (mm)
Current Range (Amps)
2.5
3.2
4.0
5.0
60 - 95
100 - 130
130 - 165
165 - 260
Notes: Welding current (Amperage)
Arc Length
To strike 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 result in poor quality welds. General rule of thumb for down hand welding is to
have an arc length no greater than the diameter of the core wire.
Electrode Angle
The angle that the electrode makes with the work is important to ensure a smooth, even
transfer of metal. When welding in down hand, fillet, horizontal or overhead the angle of the
electrode is generally between 5 and 15 degrees towards the direction of travel. When vertical
up welding the angle of the electrode should be between 80 and 90 degrees to the work
piece.
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The electrode should be moved along in the direction of the joint being welded at a speed that
will give the size of run required. At the same time, the electrode is fed downwards to keep the
correct arc length at all times. Excessive travel speeds lead to poor fusion, lack of penetration
etc, while too slow a rate of travel will frequently lead to arc instability, slag inclusions and poor
mechanical properties.
Travel Speed
Material and Joint Preparation
The material to be welded should be clean and free of any moisture, paint, oil, grease, mill
scale, rust or any other material that will hinder the arc and contaminate the weld material.
Table 6-2-2: Welding current (Amperage)
Summary of Contents for Dura ARC160
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