MIG (Metal Inert
Gas)
Welding
Short Circuit Transfer - Short circuit transfer is the most common used method whereby the wire elec
trode is fed continuously down the welding torch through to and exiting the contact tip. The wire touch
es the work piece and causes a short circuit the wire heats up and begins to form a molten bead, the
bead separates from the end of the wire and forms a droplet that is transferred into the weld pool. This
process is repeated about 100 times per second, making the arc appear constant to the human eye.
I
/
short circuit
The wire approaches the work
piece and touches the work creat
ing a short circuit between the wire
and the base metal, because there
is no space between the wire and
the base metal there is no arc and
current flows through the wire.
The pinch causes the forming
droplet to separate and fall to
wards the now creating weld pool.
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:••
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·.· .. •· ...
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, .
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The wire cannot support all the
current flow,
resistance
builds
up and the wire becomes hot
and weak and begins to melt
An arc is created at the separation of
the droplet and the heat and force
of the arc flattens out the droplet
into the weld pool. The heat of the
arc melts the end of the wire slightly
as it feeds towards the base metal
The current flow creates a mag
netic field that begins to pinch the
melting wire forming it into droplet
cycle
repeats
The wire feed speed overcomes
the heat of the arc and the wire
again approaches the work to
short circuit and repeat the cycle.
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