& Joining Methods
Arc Welding (SAW)
Similar to MIG welding, SAW involves formation
of an arc between a continuously-fed bare
wire electrode and the workpiece. The process
uses a flux to generate protective gases
and slag, and to add alloying elements to
the weld pool. A shielding gas is not required.
Prior to welding, a thin layer of flux
powder is placed on the workpiece surface.
The arc moves along the joint line and as
it does so, excess flux is recycled via
a hopper. Remaining fused slag layers can
be easily removed after welding. As the
arc is completely covered by the flux layer,
heat loss is extremely low. This produces
a thermal efficiency as high as 60% (compared
with 25% for manual metal arc). There is
no visible arc light, welding is spatter-free
and there is no need for fume extraction.