Austenitic stainless steel is stainless steel with an austenite crystal structure, in which the atoms sit in a face-centred cubic arrangement. Grades with this microstructure are typically easy to fabricate, tough, corrosion resistant, non-magnetic, and consistent in their mechanical properties across a wide temperature range.
There are many austenitic stainless steels, the most common being the 300 series (304/316) produced in large volumes for standard applications. Increasing alloying elements such as chromium and nickel raises corrosion resistance and strength.
A popular higher-performing austenitic grade is Fermonic® 50 (XM-19, Nitronic® 50, UNS S20910, 1.3964), widely used in marine applications and valve stems for its improved corrosion resistance and excellent toughness. Increasing the alloy content further gives super austenitic grades such as Alloy 254 (254SMO, 6Mo, UNS S31254, F44, 1.4547), which achieve exceptional corrosion resistance.