UNS S209101, also known as XM-19 by ASTM A2762, is a nitrogen-strengthened austenitic stainless steel with high strength and excellent corrosion resistance. Besides nitrogen (N) it also contains higher amounts of chromium (Cr), nickel (Ni), manganese (Mn), and a similar molybdenum (Mo) content compared with UNS S31603, as well as small additions of niobium (Nb) and vanadium (V). High contents of Cr, Mo and N confer this stainless steel high localized corrosion resistance. Mo, Mn and Cr increase the nitrogen solubility in iron alloys.