All about submerged arc welding

Submerged arc welding (SAW) uses heat generated by an arc formed when an electric current passes between a welding wire and the workpiece. The tip of the welding wire, the arc, and the weld joint are covered by a layer of granular flux. The heat generated by the arc melts the wire, the base metal and the flux. The flux shields the molten pool from atmospheric contamination, cleans impurities from the weld metal, and shapes the weld bead. Depending on the design of the flux, it can also add alloying elements to the weld metal to alter the chemical and mechanical properties of the weld.

Advantages of submerged arc welding

? High productivity with true deposition rates as high as 100
? Travel speeds up to 150 inches per minute single wire or as high as 220 inches per minute with multiple electrodes
? Operating factor approaching 100%
? Deepest penetration, up to 1 1/2 inches thick in a single pass
? High operator comfort, no visible arc or spatter
? High weld quality and repeatable results
? Usually fully automated process, exceptional control
? Environmentally friendly

Handling of fluxes storage

? Unopened flux bags must be stored in maintained storage conditions as follows:   Temperature: 68°F, +/- 18°F (20°C, +/- 10°C)   Relative humidity: As low as possible - not exceeding 60% max.
? Fluxes should not be stored longer than 3 years.
? The content of unheated flux hoppers must, after an 8 hours shift, be placed in a drying cabinet or heated flux hopper at a temperature of 300°F, +/- 45°F (150°C +/- 25°C).
? Remaining flux from unopened bags must be placed at a temperature of 300°F, +/- 45°F (150°C +/- 25°C).

Re-Cycling
? Moisture and oil must be removed from the compressed air used in the re-cycling system.
? Addition of new flux must be done with the proportion of at least one part new flux to one parts re-cycled flux.
? Foreign material, such as millscale and slag, must be removed by a suitable system, such as sieving or magnetic separator.

Re-Drying
? When handled and stored as above, the ESAB fluxes can normally be used straight away.
? In severe applications, stipulated by the applicable material specification, re-drying of the flux is recommended.
? Furthermore, if the flux has somehow picked up moisture, redrying can return the flux to its original moisture content.
? Re-drying shall be performed as follows:

Agglomerated fluxes: 570°F, +/- 45°F (300°C +/- 25°C) for about 2-4 hours.
Fused fluxes: 390°F, +/- 90°F (200°C +/- 50°C) for about 2-4 hours.
? Re-drying must be done either in equipment that turns the flux so that the moisture can evaporate easily or in an oven on shallow plates with a flux height not exceeding 2 in (5 cm).
? Re-dried flux, not immediately used, must be stored at 300°F, +/- 45°F (150°C +/- 25°C) before use.

Disposal
? Discard any product, residue, disposable container or liner in an environmentally acceptable manner, in full compliance with federal and local regulations.
? Please address your local disposal company for prescribed disposal.
? Information on product and residues are given in the Safety Data Sheets available through www.esabna.com/msds.