DEVELOPMENT

The principles of gas metal arc welding began to be understood in
the early 19th century, after Humphry Davy discovered the short
pulsed electric arcs in 1800[1] and then Vasily Petrov
independently produced the continuous electric arc in 1802[2]
(soon followed by Davy). In his work published in 1803 Petrov
proposed the usage of electric arc in welding, having managed to
perform a simple experimental welding.[2] But it was not until the
1880s that the technology became developed with the aim of
industrial usage. At first, the practical method of carbon arc
welding invented by Nikolay Benardos was used,[3] utilising
carbon electrodes known from the time of Davy and Petrov. By
the late 1880s, metal electrodes had been invented by Nikolay
Slavyanov (1888)[4] and C. L. Coffin (1890). In 1920, an early
predecessor of GMAW was invented by P. O. Nobel of General
Electric. It used a bare electrode wire and direct current, and used
arc voltage to regulate the feed rate. It did not use a shielding gas
to protect the weld, as developments in welding atmospheres did
not take place until later that decade. In 1926 another forerunner of
GMAW was released, but it was not suitable for practical use.[5]
It was not until 1948 that GMAW was finally developed by the
Battelle Memorial Institute. It used a smaller diameter electrode and
a constant voltage power source, which had been developed by
H. E. Kennedy. It offered a high deposition rate, but the high cost
of inert gases limited its use to non-ferrous materials and cost
savings were not obtained. In 1953, the use of carbon dioxide as a
welding atmosphere was developed, and it quickly gained
popularity in GMAW, since it made welding steel more
economical. In 1958 and 1959, the short-arc variation of GMAW
was released, which increased welding versatility and made the
welding of thin materials possible while relying on smaller
electrode wires and more advanced power supplies. It quickly
became the most popular GMAW variation. The spray-arc transfer
variation was developed in the early 1960s, when experimenters
added small amounts of oxygen to inert gases. More recently,
pulsed current has been applied, giving rise to a new method
called the pulsed spray-arc variation.[6]
As noted, GMAW is currently one of the most popular welding
methods, especially in industrial environments. It is used
extensively by the sheet metal industry and, by extension, the
automobile industry. There, the method is often used for arc spot
welding, thereby replacing riveting or resistance spot welding. It is
also popular for automated welding, in which robots handle the
workpieces and the welding gun to speed up the manufacturing
process.[7] Generally, it is unsuitable for welding outdoors,
because the movement of the surrounding air can dissipate the
shielding gas and thus make welding more difficult, while also
decreasing the quality of the weld. The problem can be alleviated
to some extent by increasing the shielding gas output, but this can
be expensive and may also affect the quality of the weld. In
general, processes such as shielded metal arc welding and flux
cored arc welding are preferred for welding outdoors, making the
use of GMAW in the construction industry rather limited.
Furthermore, the use of a shielding gas makes GMAW an
unpopular underwater welding process, but can be used in space
since there is no oxygen to oxidize the weld.