Super Duplex Stainless Steel Pren Pipes Tubing Chemical Processing

Lean duplex stainless steels: The lean duplex grades such as  S32101, S32202, S82011 and S32304 are characterized by relatively low levels of nickel and/or molybdenum. To compensate for the reduced nickel content, which is a strong austenite former, these grades have increased levels of nitrogen and manganese, which provide an acceptable austenite/ferrite phase balance.  As a group the lean grades have high strength, particularly yield strength, and exhibit a pitting and crevice corrosion resistance that is similar to, or just below that, of the Type 316L austenitic grade. Because of their relatively high yield strength, the lean DSSs are well suited for tank construction and structural applications.

Standard duplex stainless steels: The standard duplex grades typically contain 21-25% chromium, 2-3% molybdenum and 0.15% nitrogen.  Grades in this category are used widely across all industry sectors and 2205 (S32205) has become by far the most widely used duplex grade. The 2205 grade has a yield strength that is more than twice that of Type 316 and a pitting and crevice corrosion resistance that is similar to Type 904L austenitic stainless steel. Applications for standard duplex grades include tanks, piping, process vessels and structural applications.

Super duplex stainless steels: The super duplex stainless steels typically contain 25% chromium, 3.5-4.0% molybdenum, and 0.25-0.27% nitrogen. The pitting and crevice corrosion resistance of the super duplex grades are essentially equivalent to the 6% Mo super austenitic stainless steels. The most widely used super duplex stainless steel grades are the 2507 (S32750) and Z100 (S32760) grades. Common applications include piping, heat exchangers, tanks, and process vessels used for chemical processing and marine applications.

Hyper duplex stainless steels: The hyper duplex stainless steels, S33207 and S32507 are the most highly alloyed of the duplex family and contain 26-30% chromium, 3.5-5.0% molybdenum, and 0.30-0.50% nitrogen. The hyper duplex grades are designed for more aggressive acid and chloride-containing environments. They are produced in limited quantities and are currently only available as seamless tubing.