technical insight
improves resistance to pitting and crevice corrosion, particularly in chloride-containing environments, while nitrogen contributes to both strength and corrosion resistance. • As the family progresses from lean duplex to standard duplex and then to super duplex grades, the levels of chromium, molybdenum and nitrogen generally increase. This helps explain the marked improvement in corrosion resistance across the duplex range. Lean duplex grades such as 2304 typically contain about 22% chromium, with relatively modest additions of nickel and molybdenum. Standard duplex 2205 has higher nickel and molybdenum levels, while super duplex grades such as 2507 contain around 25% chromium, together with significantly higher levels of molybdenum and nitrogen. This highly alloyed chemistry enables super duplex to perform reliably in some of the most aggressive chloride environments found in industry. • One of the most striking features of duplex stainless steels is their strength. Conventional austenitic grades such as 304L and 316L typically have minimum yield strengths of about 200 MPa. By comparison, lean duplex grades commonly exceed 400 MPa, standard duplex 2205 has a minimum yield strength of about 450 MPa, and super duplex grades exceed 550 MPa. This strength gives engineers valuable design options. Components can often be made with thinner sections while still meeting structural requirements, reducing weight and material use and, in many cases, lowering total project
26
Issue 4 – 2026
Made with FlippingBook - professional solution for displaying marketing and sales documents online