Consumables for 25% Superduplex
stainless steels providing
high resistance to pitting
and stress corrosion
cracking in seawater.
The nominal composition (wt. %) of this classification is 25.5 Cr, 9.2 Ni, 3.5 Mo, 0.25 N. The sum of the
Cr + 3.3(Mo + 0.5 W) + 16 N, known as the Pitting Resistance Equivalent Number (PREN), is at least 40, thereby
allowing the weld metal to be called a “superduplex stainless steel.” This number is a semi-quantitative indicator of
resistance to pitting in aqueous chloride-containing environments. It is designed for the welding of superduplex stainless
steels UNS S32750 and 32760 (wrought), and UNS J93380, and J93404 (cast). It can also be used for the welding of UNS
S32550, J93370, and J93372 when not subject to sulfurous or sulfuric acids in service. It can also be used for the welding of carbon and low alloy steels to duplex stainless steels as well as to weld “standard” duplex stainless steel such as UNS
S32205 and J92205 especially for root runs in pipe.