UTP A 4221 is a nickel alloy TIG rod for highly corrosion resistant CrNi-MoCu alloys of the 825 type. It is used on chemical process equipment, high temperature installations and mixed joints between nickel alloys and steels.
TIG gives you full control over the heat input and a clean, smooth weld. You feed the filler into the pool by hand while the arc burns between the tungsten electrode and the weld.
- Classification EN ISO: 18274 S Ni 8065 (NiFe30Cr21Mo3)
- AWS classification: A5.14 ERNiFeCr-1
Move the pool more slowly than on steel, nickel alloys are sluggish and will not flow to the groove edges on their own. Grind the tungsten tip along its axis and hold a short arc, otherwise the pool spreads. Protect the root when you weld from one side, an oxidised underside spoils the corrosion resistance. Set current and voltage to the thickness and position, and try them on a test piece before production. The current ranges for each diameter are given in the manufacturer data sheet.
