UTP A 4221 is a solid wire in a nickel alloy for highly corrosion resistant CrNi-MoCu alloys of the 825 type. It works on boiler components, furnace parts, chemical installations and heat exchangers exposed to aggressive media.
The wire handles manual semi-automatic work and mechanised stations alike. It is fed continuously from the feeder and welded under shielding gas.
- Classification EN ISO: 18274 S Ni 8065 (NiFe30Cr21Mo3)
- AWS classification: A5.14 ER NiFeCr-1
- Shielding gas: Z-ArHeHC-30/2/0.05
Move the pool more slowly than on steel, nickel alloys are sluggish and will not flow to the groove edges on their own. Check the contact tip, a worn bore upsets wire feeding and leads to burnback. Match the feed rolls to the wire diameter and inspect the liner, wire slip shows up at once as an unstable arc. Keep the interpass temperature low and limit weaving, nickel is prone to hot cracking. The gas choice shapes the bead face and the amount of spatter, so stay with the mixture given in the classification.
