S31803 Tubing Alloy S31803 is a 22% chromium, 3% molybdenum, 5-6% nickel, nitrogen alloyed duplex stainless steel with high general, localized, and stress corrosion resistance properties in addition to high strength and excellent impact toughness. Alloy S31803 provides pitting and crevice corrosion resistance superior to 316L or 317L austenitic stainless steel in almost all corrosive media. It also has high corrosion and erosion fatigue properties as well as lower thermal expansion and higher thermal conductivity than austenitic. The advantage of a duplex structure is that it combines the favorable qualities of a ferritic alloy stress corrosion cracking resistance and high strength with austenitic alloy ease of fabrication and corrosion resistance. S31803/1.4462 Chemical composition, % according to ASTM A789 ASTM A790 C Si Mn P S Cr Mo Ni N Cu Min 21.0 2.50 4.50 0.08 Max 0.03 1.00 2.00 0.030 0.02 23.0 3.50 6.50 0.20