"Wolf Robotics has successfully integrated the robotic
process with several manufacturers of
subarc welding equipment," said a company spokesperson. "The normal restrictions
of a manual or mechanized operation are
now expanded with robotics that permits automated path following, initial
tactile joint
searching and eliminates operator supervision and involvement.
"Now you can enjoy the benefits of subarc welding and the automation of robotics to produce higher deposition rates at faster travel speeds with good penetration, excellent fusion and attractive, quality weld beads with minimal or no spatter.
According to the company, advantages of Robotic SAW include:
Less operator involvement in the actual welding process.
Eliminates the need for constant operator supervision.
Robot controls the welding process and makes necessary adjustments as needed.
Smartac search of seam ensures an accurate weld path especially important in multi-pass applications.
Flux recovery system available to reduce consumables.
Ability to have multiple stations.
Increased productivity and arc-on time.
"Submerged Arc Welding (SAW) differs from other arc-welding processes in that a blanket of fusible, granular material, commonly called flux, is used for shielding the arc and the molten metal," the spokesperson said. "The arc is struck between the workpiece and a continuously fed bare wire electrode, the tip of which is submerged in the flux. The molten weld and the arc zone are protected from atmospheric contamination by being "submerged" under the blanket of granular fusible flux that becomes conductive and provides a current path between the electrode and the work. Since the arc is completely covered by the flux, it is not visible and the weld is run without the flash, spatter and sparks that characterize the open-arc processes. The nature of the flux is such that very little smoke or visible fumes are developed. In addition, no shielding gas is needed with SAW, which saves on cost.
"Using the SAW process will realize higher deposition rates and faster travel speeds. Submerged arc is able to produce a very smooth bead with good penetration and excellent fusion. The process also produces better operator appeal than flux-cored since employees no longer have to wear protective helmets and don't have to contend with welding fumes.
"Subarc can only be accomplished in flat and horizontal positions and are examined by ultrasonic or radiographic inspection to ensure top quality.
"SAW is normally operated in the automatic or mechanized mode and restricted to straight paths. However, robotic SAW with pressurized or gravity flux feed delivery is now available which allows the robot to adjust to path variations. The process is normally limited to the 1F, 1G or the 2F positions (although 2G position welds have been done with a special arrangement to support the flux). Deposition rates approaching 100 lb/h (45 kg/h) have been reported; this compares to 10 lb/h (5 kg/h) (max) for shielded metal arc welding. Currents ranging from 200 to 1,500 A are commonly used."
Material applications include:
Carbon steels (structural and vessel construction).
Low alloy steels.
Stainless steels.
Nickel-based alloys.
Surfacing applications (wearfacing, build-up and corrosion resistant overlay of steels).
Advantages of SAW:
High deposition rates (over 100 lb/h (45 kg/h) have been reported).
High operating factors in mechanized applications.
Deep weld penetration.
Sound welds are readily made (with good process design and control).
Minimal welding fume or arc light is emitted.
"Practically no edge preparation is necessary with this process," said the spokesperson. "The process is suitable for both indoor and outdoor works. Distortion is much less and welds produced are sound, uniform, ductile, corrosion resistant and have good impact value. Single pass welds can be made in thick plates with normal equipment. The arc is always covered under a blanket of flux, thus there is no chance of spatter of weld."
For more information contact:
Wolf Robotics, Inc.
4600 Innovation Drive
Fort Collins, CO 80525-3437
970-225-7600
Fax: 970-225-7700
E-mail: sales@wolfrobotics.com