Description
UNS S31803/32205
Duplex grade UNS S31803/32205 has a microstructure that is both ferritic and austenitic at the same time. The annealed state of the alloy has about 40% to 50% ferrite in it. People who make duplex microstructures like this have the high strength of ferritic grades while still being resistant to corrosion from austenitic grades. Because stainless steel is so strong, chloride-induced stress cracking is its Achilles' heel.It's not unusual for people to use metal as a practical solution for this.
It is better at protecting itself from chloride pitting and crevice corrosion than 317L stainless steel is.
When it comes to corrosion, the alloy is very good at resisting seawater and most concentrations of sulphuric acid. As a bonus, it is also resistant to sulphide stress cracking (sour-gas environments). Many people think the high quality and performance of UNS S32205 is because of the high levels of chromium, nitrogen, and molybdenum that are in the metal.
