RAZORWELD™ ARC 630 - MMA/CAG/TIG Welder Manual
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ARC
63O
TIG WELDING GUIDE
DC TIG Welding
The DC power source uses what is known as DC (direct current) in which the main elec-
trical component known as electrons flow in only one direction from the negative pole
(terminal) to the positive pole (terminal). In the DC electrical circuit there is an electrical
principle at work which should always be taken into account when using any DC circuit.
With a DC circuit 70% of the energy (heat) is always on the positive side. This needs to be
understood because it determines what terminal the TIG torch will be connected to (this rule
applies to all the other forms of DC welding as well ).
DC TIG welding is a process in which an arc is struck between a TUNG
-
STEN electrode and the metal work piece. The weld area is shielded by
an inert gas flow to prevent contamination of the tungsten, molten pool
and weld area.
When the TIG arc is struck the inert gas is ionized and superheated
changing it’s molecular structure which converts it into a plasma stream.
This plasma stream flowing between the tungsten and the work piece is
the TIG arc and can be as hot as 19,000°C. It is a very pure and con
-
centrated arc which provides the controlled melting of most metals into
a weld pool. TIG welding offers the user the greatest amount of flexibility
to weld the widest range of material and thickness and types. DC TIG
welding is also the cleanest weld with no sparks or spatter.
The intensity of the arc is proportional to the current that flows from the
tungsten. The welder regulates the welding current to adjust the power of
the arc. Typically thin material requires a less powerful arc with less heat
to melt the material so less current (amps) is required, thicker material
requires a more powerful arc with more heat so more current (amps) are
necessary to melt the material.
30%
70%
high
current
low
current
power source
argon gas
nozzle
