MIG Welding Process, MIG welders
MIG Welding Overview
Metal Inert Gas (MIG) welding embraces a group of arc welding processes in which a continuous electrode (the wire) is fed by powered feed rolls (wire feeder) into the weld pool. An electric arc is created between the tip of the wire and the weld pool. The wire is progressively melted at the same speed at which it is being fed and forms part of the weld pool. Both the arc and the weld pool are protected from atmospheric contamination by a shield of inert (non-reactive) gas, which is delivered through a nozzle that is
concentric with the welding wire guide tube.
The Welding Process
With MIG Welders the wire is pointed in the direction of travel, this is know as the forehand technique. This lets the arc fuse to the parent metal ahead of the weld pool, thus giving the best penetration. The welder control the speed of travel to ensure the weld pool does not run ahead of the arc, which would cause a lack of fusion.
VOLTAGE control in the profile of the weld.
Wire diameter depend on the current required, below is a guide, but this will vary depending on the material and gas used
The author would like to thank:
BOC Industrial – A Member of the Linde Group –
Telwin Sp.a -
Cemont – A brand within Air Liquid Welding –
Air Products Ltd –