1 UNIONMELT®
Submerged Arc Fluxes Spoolarc®
Solid Wires and ALLOY
SHIELD® Composite Wires
The major function of a submerged arc
welding flux is to: n
Shield the molten puddle from the atmosphere.
n
Clean and deoxidize the weld puddle.
n
Control the chemistry and mechanical
properties of the weld metal. There
are two major methods by which fluxes are manufactured: BONDED
FLUXES are manufactured by dry mixing
the flux ingredients and then bonding them together
using a liquid silicate binder. The
flux pellets are then baked at a relatively low temperature to drive off the
water in the binder. The major advantages
of bonded fluxes are: n
The flux can contain metallic deoxidizers
which provide good performance over rust and mill scale.
n
The relatively coarse mesh size feeds
easily due to its uniform size. n
Bonded fluxes typically have a lower
consumption rate. The
use of bonded fluxes are not without limitation. They include:
n
Any removal of undersized particles
during recycling can change the overall chemical analysis of a
bonded flux and consequently, change
the performance characteristics of the flux. n
Segregation within the flux can occur,
making some particles richer or leaner in specific ingredients.
This is particularly critical if metals
segregate, leading to hard spot formation within the weld metal.
n
Bonded fluxes can pick up moisture
if stored improperly. They must be baked at a temperature
between 500°-800°F (260°-427°C)
to remove any suspected moisture. Continued
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