The wire approaches the work piece and
touches the work creating 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 wire cannot support all the current flow,
resistance builds up and the wire becomes
hot and weak and begins to melt
The current flow creates a magnetic field that
begins to pinch the melting wire forming it
into droplet
Wire heating
Magnetic
field pinches
wire
Short circuit
The pinch causes the forming droplet to
separate and fall towards the now creating
weld pool.
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 wire feed speed overcomes the heat of
the arc and the wire again approaches the
work to short circuit and repeat the cycle.
Droplet
separates
Arc flattens
the droplet
Cycle
repeats
MIG (Metal Inert Gas) Welding
Short Circuit Transfer
- Short circuit transfer is the most common used method whereby the wire electrode is fed continuously down the welding torch
through to and exiting the contact tip. The wire touches 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.
RAZOR MIG 250 Manual |
21
MIG WELDING GUIDE
