Duplex stainless steel – F51 / S31803 / S32205/ 1.4462

UNS S31803 and UNS S32205 are commonly referred to as Duplex 2205® material, whose “Duplex” name is derived from the mixed micro structure which contains about equal portions of ferrite and austenite. Developed more than 70 years ago in Sweden precisely for the sulfite paper industry where the Duplex’s were used to combat corrosion problems caused by chloride-bearing cooling waters and other aggressive chemical products. Since then there have been advancements in the composition such as the deliberate addition of nitrogen as an alloying agent, which afterwards quickly made Duplex the “workhorse” of stainless steels.