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NIFE-334 N

The Unitor NIFE-334 N electrode has been specially developed for cold welding of different types of cast iron especially nodular cast iron, malleable cast iron and grey cast iron. The cold welding process is normally used on large, complicated cast iron parts where the use of heat would involve considerable risk of transverse fractures. In the cold welding process, the heat transfer to the base material is kept to a minimum by welding only very short beads (2–3 cm) at a time, the bead being peened and allowed to cool before welding the next bead. Smaller parts may be hot welded i.e. preheated to approx. 500°C and continuously welded. The weld metal is easily machineable.

Large complicated parts should be cold welded.

Prepare the damage area in the following manner: – Use crack detector to find the end of the crack fracture.

– Drill a hole at the end of the crack, using a 3 mm drill, to prevent further fracturing during welding.

Smaller parts, free to

expand, may be hot welded. NB: Allow to cool off slowly.

3.01

The same welding procedure applies as for Nickel-333 N.

When welding oily cast iron, Unitor electrode CH-2-382 should be used to prepare the grooves. This is a special electrode for gouging without the use of oxygen. As well as forming a suitable welding groove, this process also burns out the oil contained in the carbon flakes, which are present in all types of cast iron. If the oil is not burnt off, it will have a tendency to surface during welding and form pores in the deposit.

A crack in cast iron. The carbon flakes in the metal are saturated with oil.

After gouging with Unitor CH-2. The oily deposits in the welding area have evaporated.

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