Specifications
| 1.4501 | X2CrNiMoCuWN 25-7-4 | Z3CND25.06Az |
| Norsok MDS D57 | SAF32760 | ASTM A276/A476 |
| UNS S32760 (Super Duplex 32760) | ASME A182 F55 | CD3MWCuN (Cast grade) |
| 25Cr | – | – |
UNS S32760
Alloy 32760 is a super duplex stainless steel that is supplied in the hot worked and solution annealed condition. Combining the advantageous characteristics of austenitic and ferritic grades, it offers exceptional properties. With higher levels of chromium, molybdenum, and nitrogen, it achieves a Pitting Resistance Equivalent number (PREN) of & providing superior resistance to pitting and crevice corrosion compared to both austenitic and duplex stainless steels in nearly all corrosive environments. It also boasts a Critical Pitting Temperature exceeding 50°C, indicating its high corrosion resistance. Notably, Alloy 32760 exhibits higher strength than both austenitic and 22% Cr duplex stainless steels. It is listed in NACE MR 0175 for sour service and has gained ASME approval for pressure vessel applications, further attesting to its suitability for a wide range of demanding environments.
Chemical Composition Limits
| Â | Cr | Ni | Mo | Co | Nb (+Ta) | Ti | V | W | Cu | C | Mn | N | Si | P | S | Fe | Al |
| Min | 24.00 | 6.00 | 3.00 | – | – | – | – | 0.50 | 0.50 | – | – | 0.20 | 0.10 | – | – | – | – |
| Max | 26.00 | 8.00 | 4.00 | – | – | – | – | 1.00 | 1.00 | – | 1.00 | 0.30 | 0.80 | 0.025 | 0.005 | Bal | – |
Mechanical Properties
| 0.2% Proof Stress | 550 N/mm2 | 79.8 ksi |
| Tensile Strength | 750 N/mm2 | 108.8 ksi |
| Elongation, 5.65√S0 | 25% | – |
| Reduction of area | 45% | – |
| Hardness (Brinell) | 270 max. | – |
| Impact Strength (Room Temp) | 80J | 59 lb.ft |
| Impact Strength (-46oC) | 60J av (45J min) | 44 lb.ft av (33 lb.ft min) |
Physical Properties
| Density (Kg/m3) | 7810 |
| Magnetic Permeability (20°C) | 33 |
| Young’s Modulus (kN/mm2) | 199 |
| Specific Electrical Resistance, 20°C (µΩ.m) | 0.8 |
| Mean coefficient of thermal expansion, 20-300°C (m/m/oC) | 11.1 x 10-6 |
| Specific Heat, 20°C (J/kg.K) | 475 |
| Thermal conductivity, 20°C (W/m.K) | 14.2 |
| Fracture Toughness, kQ (MPa/m2) | 98 |
Key Features
- Excellent corrosion resistance in a wide variety of corrosive chemicals.
- Pitting Resistance Equivalent number (PREN) of >40.
- Outstanding resistance to pitting and crevice corrosion in seawater and other chloride containing environments.
- Critical Pitting Temperature exceeding 50°C.
- High strength compared to austenitic and 22%Cr duplex stainless steels.
- Excellent ductility and impact strength at both ambient and sub-zero temperatures.
- High resistance to abrasion, erosion and cavitation erosion.
- Excellent resistance to stress corrosion cracking in chloride containing environments.
- Listed in NACE MR 0175 for sour service
- ASME Approval for Pressure Vessel application.
Applications
- Process industry components in nitric acid, dioxide, polypropylene & PVC production, caustic evaporators.
- Equipment handling organic & fatty acids
- Marine industry and shipbuilding propellers, shafts, rudders, shaft seals, pumps, bolts, fasteners, valves, instrumentation.
- Oil and chemical tankers
- Oil & Gas industry pumps, valves, pipe, vessels, wellhead equipment, subsea equipment.
- Pollution control systems, fans and pumps, wet scrubbers, incinerators, flue gas desulphurisation (FGD).
- Pulp & paper industry components such as black liquor heater tubes, digester blow valves, rotary feed valves, I.D.fans, brownstock washers, precipitators, bleaching components.
- Food Industry applications including sugar cane centrifuges, corn and vegetable processing plant.
- Agrochemicals production such as fertilisers (based on wet phosphoric acid).
- Sewage treatment, seawater cooling, desalination plants.