Advanced Welding Processes: Technologies and Process Control

Slag deposit
on weld surface
An introduction to welding processes 11
Weld metal
Electrical
contact
Submerged arc welding (SAW) {12}
Submerged arc welding is a consumable electrode arc welding process in
which the arc is shielded by a molten slag and the arc atmosphere is generated
by decomposition of certain slag constituents (Fig. 1.9). The filler material
is a continuously fed wire and very high melting and deposition rates are
achieved by using high currents (e.g. 1000 A) with relatively small-diameter
wires (e.g. 4 mm).
The significant features of the process are:
∑ high deposition rates;
∑ automatic operation;
∑ no visible arc radiation;
∑ flexible range of flux/wire combinations;
∑ difficult to use positionally;
∑ normally used for thicknesses above 6 mm.
Electrode core wire
Flux coating
Transferring droplet
Arc
1.8 Shielded metal arc welding [or manual metal arc welding
(MMAW)].
The main applications of submerged arc welding are on thick section plain
carbon and low-alloy steels and it has been used on power generation plant,
nuclear containment, heavy structural steelwork, offshore structures and
shipbuilding. The process is also used for high-speed welding of simple