In the 1980s, the name “Super-Duplex” was first used to denote highly alloyed, high-performance Duplex steel with a pitting resistance equivalent of >40 (based on Cr% + 3.3Mo% + 16N%). Duplex stainless steel is based around a composition of 22% chromium, whereas super duplex stainless steel is based around a composition of 25% chromium. By increasing the chromium content, the level of pitting corrosion resistance is also increased. Super Duplex stainless steel is often employed in the oil and gas industry, heat exchangers, offshore platforms, chemical processing equipment, boilers, and pressure vessels. However, to retain the favourable balance of austenitic and ferritic microstructures, it is also necessary to increase the content of nickel and other elements.
By increasing the nickel and molybdenum content in the alloy, the cost of super duplex alloys tends to increase as a rare and expensive element. On the other hand, super Duplex stainless steel has all of the same benefits as Duplex steel. The main difference is that this metal has a higher chromium and molybdenum content, increasing corrosion resistance.
Here are some super duplex steel products manufactured by Gautamtubes, visit the pages for product features