BOC Smootharc S 312 Electrode

Smootharc S 312 is a rutile coated, AC / DC electrode that deposits a 29 Cr / 9 Ni austenitic / ferritic stainless steel weld metal with a ferrite content of FN 50. The resultant weld metal is high strength with high ductility and the structure is highly resistant to hot cracking and extremely tolerant of dilution from medium and high carbon steels. The electrode is very easy to strike and restrike. Welding performance is excellent, with a very smooth, low spatter arc producing a finely rippled bead surface with excellent slag detachability.

These electrodes are available in the following sizes:

• Part no: 188122VP – 2.5mm 1.7kg
• Part no: 188123VP – 3.2mm 2kg
• Part no: 188124VP – 4.0mm 2kg

• Smootharc S 312 is a universal electrode specifically designed for welding steels of poor weldability. The electrode is suitable for welding armour plate, austenitic manganese steel, medium and high carbon hardenable steels, tools, dies, springs etc that may be of unknown composition. It is also suitable for welding dissimilar steels (e.g. stainless to mild steel).
• Stainless steel electrodes can be welded using either AC or DC, with as short an arc as possible to minimise alloy loss across the arc and to control ferrite level. When using AC, a slightly higher current setting may be required. When welding in the flat position stringer beads should be used and, if weaving is required, this should be limited to 2 times the electrode diameter.
• Smootharc S 312 electrodes are packaged in vacuum sealed packs. For critical applications in damp environments, once the seal is broken, electrodes should be stored in heated cabinets at 70–120°C.
• All electrode coatings are hydroscopic and, when left in the opened state for a period of time, will absorb moisture. Austenitic materials are generally insensitive to the presence of hydrogen. However, moisture in the electrode coating can lead to porosity in the weld metal. Start porosity is generally indicative of damp electrodes and is more common in fillet welds than in butt welds where pores only occur at high moisture contents. Electrodes that have been stored outside of their vacuum sealed packs and have become damaged by moisture pick-up can be redried at temperatures of 300–350°C for 1–2 hours. Redrying should be restricted to a maximum of 3 cycles.