Advanced Welding Processes: Technologies and Process Control

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Advanced welding processes
Excess
flux
Solidified
slag
Weld
metal Weld
pool
1.9 Submerged arc welding.
Contact tube
Arc
Filler
wire
Flux hopper
geometric seams in thinner sections, for example in the fabrication of pressure
containers for liquefied petroleum gas. Like shielded metal arc welding, with
suitable wire/flux combinations, the process may also be used for surfacing.
Gas metal arc welding (GMAW) {13}
In gas metal arc welding [also known as metal inert gas (MIG) or metal
active gas (MAG) welding in Europe; the terms semi-automatic or CO2 welding are sometimes used but are less acceptable] the heat generated by an
electric arc is used to fuse the joint area. The arc is formed between the tip
of a consumable, continuously fed filler wire and the workpiece, and the
entire arc area is shielded by an inert gas. The principle of operation is
illustrated in Fig. 1.10.
Some of the more important features of the process are summarized below:
Flux
∑ low heat input (compared with SMAW and SAW);
∑ continuous operation;
∑ high deposition rate;