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12
Electrode Size
The size of the electrode generally depends on the thickness
of the section being welded, and the thicker the section the
larger the electrode required. The table gives the maximum
size of electrodes that maybe used for various thicknesses of
section base on using a general purpose type 6013 elec-
trode.
Welding Current (Amperage)
Electrode Selection
As a general rule, the selection of an electrode is straight forward,in that it is only a matter of selecting an elec-
trode of similar composition to the parent metal. However, for some metals there is a choice of several electrodes,
each of which has particular properties to suit specic classes of work. It is recommend to consult your welding
supplier for the correct selection of electrode.
ARC (Stick) Welding Fundamentals
Average Thickness Maximum Recommended
of Material Electrode Diameter
0.03 - 0.07 inches
0.07 - 0.19 inches
0.19 - 0.31 inches
0.31 - > inches
0.09 inches
0.12 inches
0.15 inches
0.19 inches
Electrode Size Current Range
ø mm (Amps)
60 - 100
100 - 130
130 - 165
165 - 260
0.09 inches
0.12 inches
0.15 inches
0.19 inches
Correct current selection for a particular job is an important
factor in arc welding. With the current set too low, diculty
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 prole 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.
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 nish 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, llet, 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 be-
tween 80 and 90 degrees to the work piece.
Travel Speed
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. Exces-
sive 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.
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. Joint preparation will depend on the method
used include sawing, punching, shearing, machining, ame cutting and others. In all cases edges should be clean
and free of any contaminates. The type of joint will be determined by the chosen application.
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