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This process was developed between the two world wars for
the welding of heavy sections in ships, combat vehicles and pressure
vessels. In this process, an arc is struck between a continuously
fed bare wire electrode and the work piece. The arc and molten metal
are submerged in a blanket of granular fusible flux. The flux has
a similar composition to that of the coating materials used in the
manufacture of manual arc welding electrodes. It serves to provide
a good arc stability and the required chemical and mechanical properties
of the welds by using relatively high current densities deep penetrations
and thus, high welding speeds can be obtained.
Submerged arc welding may be used with semi-automatic as well as
fully automatic processes. The automatic submerged arc welding process
is used extensively for welding plain carbon steels, low-alloyed
steels, high strength low-alloyed steels and stainless steels. This
process is most suitable for making flat butt or fillet welds. The
main application areas of this process are circumferential weldings
of large diameter pipes and tanks, longitudinal welding of fuel
storage tanks, ship plates. " I " beams and other heavy
sections. This process is also used for the hard surfacing of large
parts, such as the wear parts in earth moving and mining equipment,
hot drawing cylinders in the steel industry, etc. |
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