Nitronic 50 and Nitronic 60 are both austenitic stainless steels that use nitrogen as an alloying element, but they are chosen for very different reasons: Nitronic 50 for high strength and corrosion resistance, Nitronic 60 for its resistance to galling.
Nitronic 50
Nitronic 50 (Nit50, UNS S20910, DIN 1.3964, ASTM A182 XM19) is widely used for valve bodies and stems. It provides almost double the yield strength of common austenitic grades such as Alloy 304 and Alloy 316L, while keeping excellent ductility and toughness at both elevated and cryogenic temperatures. Its PREN is above 34, comparable with a duplex stainless steel such as S32205 and far better than the 25 achieved by a regular Alloy 316L. Nitronic 50 is identified as suitable for hydrogen service and is listed in NACE MR0175 for sour service, given its resistance to sulphide stress cracking.
Nitronic 50 can be supplied in several conditions. In the annealed condition it is relatively low strength but far easier to machine into complex components. The more popular condition is High Strength, also called Warm Worked or Hot Rolled.
Nitronic 60
Nitronic 60 (UNS S21800) is a specialist alloy used where resistance to galling is critical. Galling is when two metal surfaces join unintentionally, caused by micro-welding at localised points of contact; the damage usually appears as tearing when the surfaces are pulled apart. It is more likely when components stay in intimate contact for extended periods, typically under load.
Resistance to galling therefore matters for components such as couplings, connectors, stab plates and dry-break couplings, which may stay connected for long periods but need to disconnect quickly. Nitronic 60 is heavily alloyed with silicon and manganese to provide that resistance.
What we stock
We carry Nit50 in both Annealed and High Strength condition as solid round bar up to 10" (254mm) diameter. Nit 60 is stocked in a range of sizes to suit the most common applications.