 A submerged arc welder used for training.
 Close-up view of the control panel. Submerged Arc Welding (SAW) is a common arc welding process. It requires a continuously fed consumable solid or tubular (flux cored) electrode. The molten weld and the arc zone are protected from atmospheric contamination by being “submerged” under a blanket of granular fusible flux. When molten, the flux becomes conductive, and provides a current path between the electrode and the work. Download high resolution version (1585x1559, 778 KB) A Lincoln Submerged Arc Welding machine. ...
Download high resolution version (1585x1559, 778 KB) A Lincoln Submerged Arc Welding machine. ...
Download high resolution version (776x773, 213 KB) Close-up shot of the control panel for the submerged arc welder. ...
Download high resolution version (776x773, 213 KB) Close-up shot of the control panel for the submerged arc welder. ...
Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. ...
In metallurgy, flux is a substance which removes passivating oxides from the surface of a metal or alloy. ...
SAW is normally operated in the automatic or mechanized mode, however, semi-automatic (hand-held) SAW guns with pressurized or gravity flux feed delivery are available. 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 1500 A are commonly used; currents of up to 5000 A have been used (multiple arcs). Shielded metal arc welding Shielded metal arc welding (SMAW), also known as manual metal arc (MMA) welding or informally as stick welding, is a manual arc welding process that uses a consumable electrode coated in flux to lay the weld. ...
In electricity, current is the rate of flow of charges, usually through a metal wire or some other electrical conductor. ...
Single or multiple (2 to 5) electrode wire variations of the process exist. SAW strip-cladding utilizes a flat strip electrode (e.g. 60 mm wide x 0.5 mm thick). DC or AC power can be utilized, and combinations of DC and AC are common on multiple electrode systems. Constant Voltage welding power supplies are most commonly used, however Constant Current systems in combination with a voltage sensing wire-feeder are available. A high output constant current welding power supply for use with GTAW and SMAW A welding power supply is an electrical device that provides an electrical current to perform welding procedures which require electricity. ...
Material applications - 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);
- High speed welding of thin sheet steels at over 100 in/min (2.5 m/min) is possible;
- Minimal welding fume or arc light is emitted.
· Practicaly no edge preparation is necessary · The process is suitable for both indoor and outdoor works. · Distortion is much less. · 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.
Limitations of SAW - Limited to ferrous (steel or stainless steels) and some nickel based alloys;
- Normally limited to the 1F, 1G, and 2F positions;
- Normally limited to long straight seams or rotated pipes or vessels;
- Requires relatively troublesome flux handling systems;
- Flux and slag residue can present a health & safety issue;
- Requires inter-pass and post weld slag removal.
Key SAW process variables - Wire Feed Speed (main factor in welding current control);
- Arc Voltage;
- Travel Speed;
- Electrode Stick-Out (ESO) or Contact Tip to Work (CTTW);
- Polarity and Current Type (AC or DC).
Other factors - Flux depth/width;
- Flux and electrode classification and type;
- Electrode wire diameter;
- Multiple electrode configurations.
External links
Additional reading American Welding Society, Welding Handbook, Vol 2 (9th ed.)
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