Duplex stainless steel is a very useful metal that is used the world over. It gets its name from the fact that it consists of two different grades of metal. Essentially, Duplex is a Fe-Ni-Cr alloy that has a two-phase ferritic-austenitic stainless-steel microstructure when it is at room temperature.
What is duplex and super duplex stainless steel?
Super Duplex stainless steels are based around an alloying addition of 25% chromium, whereas duplex stainless steels are based around an alloying addition of 22% chromium. By increasing the chromium content, the level of pitting corrosion resistance is also increased.