S20910 is the Unified Numbering System (UNS) designation for a higher-alloyed austenitic stainless steel, most commonly known as Nitronic® 50. We stock it as XM19 (Fermonic® 50, UNS S20910) in both the annealed and hot rolled condition.
The UNS system was created by a number of trade groups in the 1970s to reduce confusion caused by the same alloy being called different things, or different alloys sharing a name. Each metal is given a letter followed by five numbers, where the letter indicates the family - S for stainless steels.
What is Nitronic 50?
Nitronic 50 is a higher-performance austenitic stainless steel that provides roughly twice the yield strength of regular 3xx series grades, together with improved corrosion performance.
Like some super duplex stainless steels, it uses an increased nitrogen content to raise strength, so it is sometimes described as a nitrogen-strengthened alloy. Additions of manganese also push up the strength through solid solution strengthening.
Corrosion resistance
Compared with Alloy 316L, S20910 contains increased chromium and molybdenum, which support its improved corrosion resistance. Where Alloy 316L has a Pitting Resistance Equivalent Number (PREN) of 25, the PREN of Nitronic 50 is 34.
It is listed in NACE MR0175 for sour service applications, given its ability to resist sulphide stress cracking, and is widely used across marine and industrial applications.
What we stock
We carry a significant stock of XM19 (Fermonic® 50, UNS S20910) in both the annealed and hot rolled condition, from 5/8" (15.875mm) up to 10" (254mm) in a large number of incremental sizes. See our full range of stainless steels.