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IDUPLEX-222

Unitor Iduplex-222 is a TIG rod for welding duplex stainless steel grades like WNr.1.4462, UNS 31803. The deposit offers elevated mechanical strength and toughness resistance to stress corrosion cracking. Application areas are similar to those for coated electrode Duplex-325 N, but with the advantages TIG can offer. When welding thin sheets and pipes (less than 2 mm) it is always an advantage to use TIG. This filler rod may also be used as a root bead when welding thicker sheets with prepared U or V-grooves. The groove can subsequently be filled, using coated electrodes. Burn-through is difficult to avoid when using coated electrodes on thin sheets. The rod can also be used for welding duplex to mild steel and duplex to stainless steel (AISI 304, AISI 316 LN). For TIG welding connect the torch to DC negative polarity. A pointed Tungsten electrode alloyed with lanthanum (Gold colour code) must be used. Shielding gas must be Argon. Interpas temperature should not exceed 250°C during welding. After welding, remove discoloration by using Unitor Pickling Paste.

Included angle

Root Gap

When welding V and U butt welds the included angle and root gap is slightly ­bigger than for AISI 316 stainless steel.

Rapid cooling of weld deposit should be avoided as the material structure may suffer

3.02

Note: The back of the weld will oxidize (oxygen will attack the hot surface) unless it is shielded. In piping this can be done by blocking the pipe ends and introducing Argon gas. Remember there is considerably more shrinkage in duplex stainless steel than in mild steel and the tacks should therefore be placed as closely as possible

Remember to only use stainless steel wire brushes and chipping hammers when working with stainless steel

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