Submerged arc welding (SAW) has unique advantages over gas shielded welding processes. The blanket of slag protects the weld metal longer than a gas shield which results is less surface oxidation.
Many weld defects are traceable to oxide inclusions which is one of the reasons SAW is known for reliable weld quality.
Recently advances in motion control have been applied to SAW. This has caused renewed interest in the process. Precise torch and part motion are difficult to achieve without computer control as the weld is not visible to the operator.
The use of a single computer to control all weld variables including voltage, amperage, wire speed and travel speed improves control of total weld heat input.
Once a system incorporates intelligent servo motion other features such as torch height control and oscillation are possible.
Oscillation allows the engineer to reduce weld thickness without having to resort to higher arc voltages. Lower arc voltages result in lower heat inputs which typically result in improved HAZ notch toughness and reduced grain size.
Modern controls technology applied to a 76 year old welding process will insure that submerged arc welding will continue to be a viable joining and overlay technique in the 21 century.