Duplex &
Super Duplex Steel
High-strength stainless steel alloys with a balanced austenitic and ferritic structure, engineered for superior resistance to pitting, stress corrosion and harsh chloride environments.
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Strength • Corrosion Resistance
Duplex & Super Duplex Steel Strength Meets Corrosion Resistance.
Duplex and super duplex steel are two types of stainless steel alloys that contain higher levels of chromium and molybdenum compared to standard austenitic stainless steels. These alloys also have a mixed microstructure of both austenitic and ferritic phases, which gives them unique properties.
Duplex stainless steel typically contains around 22% chromium and 5% nickel, as well as 3% to 4% molybdenum. This combination of elements provides high resistance to stress corrosion cracking, pitting, and crevice corrosion. Duplex stainless steel is also known for its high strength and toughness, making it a popular material for applications in the oil and gas, chemical, and marine industries. Super duplex stainless steel contains even higher levels of chromium, nickel, and molybdenum, typically around 25%, 7%, and 4% respectively. This alloy offers even greater resistance to corrosion, particularly in harsh environments such as seawater and acidic or chloride-containing solutions. Super duplex stainless steel is commonly used in offshore oil and gas platforms, chemical processing plants, and desalination plants.
Duplex & Super Duplex Steel Products.
Explore our range of duplex and super duplex steel pipe fittings engineered for corrosion resistance, strength and demanding industrial applications.
Duplex & Super Duplex Steel Technical Properties
Technical reference data covering equivalent grades, chemical composition, and key physical properties of Duplex and Super Duplex stainless steels.
Equivalent Grades
Standard grade references for Duplex and Super Duplex steel materials.
| Standard | Werkstoff Nr. | UNS |
|---|---|---|
| Duplex S31803 | 1.4462 | S31803 |
| Duplex 2205 | 1.4462 | S32205 |
| SUPER DUPLEX | ||
| Super Duplex S32750 | 1.4410 | S32750 |
| Super Duplex S32760 | 1.4501 | S32760 |
Chemical Composition
Chemical composition reference for Duplex and Super Duplex grades.
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | Fe |
|---|---|---|---|---|---|---|---|---|---|---|
| DUPLEX STEEL | ||||||||||
| S31803 | 0.030 max | 2.00 max | 1.00 max | 0.030 max | 0.020 max | 22.0 – 23.0 | 3.0 – 3.5 | 4.50 – 6.50 | 0.14 – 0.20 | 63.72 min |
| S32205 | 0.030 max | 2.00 max | 1.00 max | 0.030 max | 0.020 max | 21.0 – 23.0 | 2.50 – 3.50 | 4.50 – 6.50 | 0.8 – 0.20 | 63.54 min |
| SUPER DUPLEX STEEL | ||||||||||
| S32750 | 0.030 max | 1.20 max | 0.80 max | 0.035 max | 0.020 max | 24.00 – 26.00 | 3.00 – 5.00 | 6.00 – 8.00 | 0.24 – 0.32 | 58.095 min |
| S32760 | 0.05 max | 1.00 max | 1.00 max | 0.030 max | 0.010 max | 24.00 – 26.00 | 3.00 – 4.00 | 6.00 – 8.00 | 0.20 – 0.30 | 57.61 min |
Mechanical Properties
Density and melting point reference values for Duplex and Super Duplex grades.
| Grades | Density (g/cm³) | Density (lb/in³) | Melting Point (°C) | Melting Point (°F) |
|---|---|---|---|---|
| DUPLEX STEEL | ||||
| S31803 / S32205 | 7.805 | 0.285 | 1420 – 1465 | 2588 – 2669 |
| SUPER DUPLEX STEEL | ||||
| S32750 / S32760 | 7.8 | 0.281 | 1350 | 2460 |