The Gas Metal Arc Welding process is where an arc is struck between the base metal and a continuously supplied consumable wire. Which provides filler metal for the weld and this process is one of the oldest ways to perform welding; it is basically performed on the non-ferrous metal. The Gas metal arc welding can open up the possibilities to weld all metal for which the consumables are available, initially, the process was mainly performed on aluminum and stainless steel with inert gas shielding.
The electrode is bare, containing no coating or core. The shielding, to protect the molten metal from reacting with constituents of the atmosphere, is supplied by an external gas, usually containing one or a mixture of the following: helium, argon, or carbon dioxide.
A major amount of fume can be generated when welding with this process. Most of the fume generated during the Gas Metal Arc Welding process is derived from the consumption of the electrode and not from the base metal.
This process can be performed in both semi-automatic and automatic. The basic equipment for a semi-automatic setup includes a wire feeder which helps in ensuring the consonant supply of voltage and speed, a supply of wire, a welding gun and a shielding gas cylinder. In automatic welding, it does not involve any human labor, aside from identifying when to begin.
The GMAW/MIG process has many advantages like it is an automated /semi-automated process, good for thin metals or for thick joints, flexibility (can weld in any position), cost-effectiveness with minimal waste.
That is why it is generally used for pipe welding/pipe joints, auto-industry, manufacturing, shipbuilding, railways, construction and also for underwater welding. To maintain a stable arc the appropriate amount of power is supplied by internal circuitry.