GAS METAL ARC WELDING
1.) GAS METAL ARC WELDING (GMAW)
1.) Gas metal arc welding (GMAW), is sometimes referred to as
◦Metal inert gas (MIG) welding or
◦Metal active gas (MAG) welding
2.) GMAW is a semi-automatic or automatic arc welding process in which a continuous and consumable wire electrode and a shielding gas are fed through a welding gun.
3.) A constant voltage, direct current power source is most commonly used with GMAW.
2.) GMAW Operation / Principal
3.) Equipment’s for GMAW
4 wheel wire drive unit
GMAW Welding Gun
3.and threaded metal nut insert (yellow)
4.Shielding gas nozzle
Arc Welding Gun Nomenclature
4.) GMAW Advantages and Limitation:-
5.) GMAW –Mode of Transfer
There are four primary methods of metal transfer in GMAW. They are:
GMAW – Metal Transfer Mode
Each transfer mode has distinct properties, advantages and limitations.
The mode of transfer is determined by a number of factors:
◦Magnitude, type and polarity of welding current
◦Electrode extension and
◦Shielding gas composition
6.) GMAW -Process variables
The following are some of the process variables that affect weld penetration, bead geometry and overall weld quality.
Welding Current (Electrode feed speed)
Arc voltage (Arc length)