Union S 2 Si is a submerged arc (SAW) wire for mild steel. It is used in steel construction, on tanks, pipework and series production.
The wire works as a set with a matched flux, which decides the mechanical properties of the weld. The copper coated surface improves current pick-up in the contact tip and smooth feeding.
Classification EN ISO: 14171-A S2Si
AWS classification: A5.17 / SFA-5.17 EM12K
Shielding: flux matched to the wire, no shielding gas
Diameters: 2.0 / 2.4 / 3.0 / 3.2 / 4.0 mm
On heavier sections and in a cold workshop plan the preheating, so that the risk of cold cracking stays down. 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. Match the flux to this wire and check how dry it is, drying the flux decides the hydrogen level in the weld.
Manufacturer datasheet
Chemical composition and properties from the manufacturer datasheet
Typical weld metal values from the voestalpine Böhler Welding data sheet, issue 02/2022. The minimum or the range guaranteed by the maker is given in brackets. The figures depend on the heat treatment condition and the shielding gas stated in the row and do not replace testing the joint to your own WPS.
Chemical composition, wt.-%
C
Si
Mn
0,10
0,30
1,10
Fits
For which materials and machines
Base materials
Material group: mild and low-alloy steels. The exact grades and thicknesses are in the manufacturer data sheet, and for an unusual joint call us, we will pick the filler metal.
Process and machines
Submerged arc wire, works on any sound machine for this process: welders.
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