Union S 3 Si is a submerged arc (SAW) wire for mild steel. It is used in steel construction, on tanks, pipework and series production.
Submerged arc welding gives a very high deposition rate on long, repeatable welds. The copper coated surface improves current pick-up in the contact tip and smooth feeding.
- Classification EN ISO: 14171-A S3Si
- AWS classification: A5.17 / SFA-5.17 EH12K
- Shielding: flux matched to the wire, no shielding gas
- Diameters: 2.0 / 2.5 / 3.0 / 3.2 / 4.0 / 4.8 mm
Clean rust, paint and grease out of the groove, contaminated plate gives porosity even with the parameters set correctly. Keep an even flux layer over the arc, too thin a layer exposes the arc and too thick a one spoils the bead shape. Watch the wire stick-out and the position of the head against the weld centre line, under a flux you cannot see the pool and a mistake shows only after the slag is chipped off.
