Duplex  Technical Data Duplex is a stainless steel designed to combine improved resistance to stress corrosion cracking, pitting, crevice corrosion and high strength when compared with other stainless alloys. With its austenitic ferritic chromium, nickel, molybdenum composition duplex stainless steel alloy resists chloride environments and sulphide stress corrosion. Duplex stainless steel is designed to combine improved resistance to stress corrosion cracking, pitting, crevice corrosion and high strength when compared with other stainless alloys. Duplex resists chloride environments and sulphide stress corrosion. Duplex steel has a ductile/brittle transition at approximately -50°C. Duplex is also roughly double the strength of standard austenitic stainless steels. TYPICAL ANALYSIS             C. Mn. P. S. Si. Cr. Ni. Mo. N. 0.03% max. 2.00% max. 0.03% max. 0.02% max. 1.00% max. 21.00-   23.00% 4.50-   6.50% 2.50-   3.50% 0.08-   0.20% Typical Mechanical Properties     Tensile Strength N/mm2 620 min.   0.2% Proof Stress N/mm2 448 min.   Elongation 25 min.   Hardness (Brinell 290 max. Heat Treatment. Solution annealed at 1020°C - 1100°C Water Quench Copyright 2008 Disclaimer    Duplex Stainless Steel Grades UNS S31803 31803 F51 Sandvik 2205 BS EN 1.4462 SS 2377 DIN X2CrNiMoN 22.5.3 AFNOR Z2CND 22.05.03 BS970 318S13