Tungsten
Inert Gas Welding for TIG as short name is a process of welding by using
tungsten electrode under gas protection. This process can also be called as
GTAW(Gas Tungsten Arc Weld).
The
Operation is as following:
Manual
gas tungsten arc welding is a relatively difficult welding method, due to the
coordination required by the welder. Similar to torch welding, TIG normally
requires two hands, since most applications require that the welder manually
feed a filler metal into the weld area with one hand while manipulating the
welding torch in the other. Maintaining a short arc length, while preventing
contact between the electrode and the workpiece, is also important.
To
strike the welding arc, a high frequency generator (similar to a Tesla coil)
provides an electric spark. This spark is a conductive path for the welding
current through the shielding gas and allows the arc to be initiated while the
electrode and the workpiece are separated, typically about 1.5–3 mm
(0.06–0.12 in) apart.
Once
the arc is struck, the welder moves the torch in a small circle to create a
welding pool, the size of which depends on the size of the electrode and the
amount of current. While maintaining a constant separation between the
electrode and the workpiece, the operator then moves the torch back slightly
and tilts it backward about 10–15 degrees from vertical. Filler metal is added
manually to the front end of the weld pool as it is needed.
Welders
often develop a technique of rapidly alternating between moving the torch
forward (to advance the weld pool) and adding filler metal. The filler rod is
withdrawn from the weld pool each time the electrode advances, but it is always
kept inside the gas shield to prevent oxidation of its surface and
contamination of the weld. Filler rods composed of metals with a low melting
temperature, such as aluminum, require that the operator maintain some distance
from the arc while staying inside the gas shield. If held too close to the arc,
the filler rod can melt before it makes contact with the weld puddle. As the
weld nears completion, the arc current is often gradually reduced to allow the
weld crater to solidify and prevent the formation of crater cracks at the end
of the weld.
Chinatungsten
can provide you many kinds of tungsten electrodes for GTAW welding:
Pure
tungsten electrode (WP)
Thorium
tungsten electrode (WT20)
Cerium
tungsten electrode (WC20)
Lanthanum
tungsten electrode (WL15, WL20)
Zirconium
tungsten electrode (WZ3, WZ8)
Yttrium
tungsten electrode (WY20)
Composite
tungsten electrode
