UNS N08031 Corrosion-Resisting Superalloy Bars and Plates
This high-chromium nickel-molybdenum-copper solid-solution corrosion-resistant alloy adopts composite chromium, molybdenum and copper alloying design. It delivers superior resistance to highly oxidizing mixed acids, phosphoric acid, fluorine-containing media, seawater pitting and crevice corrosion. With low-carbon stabilization design, it possesses excellent weldability and hot/cold formability, stable high-temperature microstructure and outstanding chloride stress corrosion cracking resistance, suitable for heavy-load pressure-bearing service under severe corrosive environments.
Applications of UNS N08031
Widely applied in wet-process phosphoric acid plants, pickling lines, flue gas desulfurization (FGD) equipment, seawater desalination heat exchangers, fluorine-containing chemical reactors and oxidizing mixed acid heat exchange components. It is a dedicated critical pressure-bearing alloy for service exposed to highly oxidizing acid, chloride and fluorine corrosion.
Equivalent Grades and Commonly Used Specifications of UNS N08031
| Steel Grade | Specification | Specification Name |
| UNS N08031 | ASTM B564 | Standard Specification for Nickel Alloy Forgings |
| ASTM B625 | Standard Specification for Ni-Fe-Cr-Mo-Cu-N Low-Carbon Alloy, Ni-Fe-Cr-Si Alloy, Cr-Ni-Fe-N Low-Carbon Alloy, Fe-Ni-Cr-Mo-Cu-N Alloy, and Ni-Fe-Cr-Mo-N Alloy Plate, Sheet, and Strip | |
| ASTM A276-2025 | Standard Specification for Stainless Steel Bar and Shape | |
| ASTM B649 | Standard Specification for Ni-Fe-Cr-Mo-Cu-N Low-Carbon Alloy and Cr-Ni-Fe-N Low-Carbon Alloy Bar and Wire, Ni-Cr-Fe-Mo-N Alloy Wire, and Ni-Fe-Cr-Mo-N Alloy Bar | |
| ASTM A965 | Standard Specification for Steel Forgings, Austenitic, for Pressure and High Temperature Parts | |
| ASTM B619 | Standard Specification for Welded Nickel and Nickel-Cobalt Alloy Pipe | |
| ASTM B622 | Standard Specification for Seamless Nickel and Nickel-Cobalt Alloy Pipe and Tube | |
| ASTM B366 | Standard Specification for Factory-Made Wrought Nickel and Nickel Alloy Fittings | |
| Products produced as per other specifications or technical agreements (if need) are available. | ||
Typical Chemical Composition of UNS N08031
|
Elements |
C | Mn | P | S | Si | Ni | Cr | Mo | Cu | N |
Fe |
|
Mass Fraction% |
≤0.015 | ≤2.00 | ≤0.020 | ≤0.010 | ≤0.30 | 30.00~32.00 | 26.00~28.00 | 6.00~7.00 | 1.00~1.40 | 0.15~0.25 |
Balance |
| Products produced as per other specifications or technical agreements (if need) are available. | |||||||||||
Typical Heat Treatment Condition and Mechanical Properties of UNS N08031
|
Delivery Condition |
Mechanical Properties and Hardness of Heat-Treated Specimens | ||||||
| Rp0.2/(N/mm2) | Rm/(N/mm2) | A/% | Zb/% | Aku2d/J | HBW |
HRC |
|
|
Cold Finished and Hot Finished Annealed |
≥270 | ≥650 | ≥40 | / | / | / |
/ |
| Products produced as per other specifications or technical agreements (if need) are available. | |||||||
Product Forms and Size Range of UNS N08031
|
Product forms |
Size range |
|
Bars |
Diameter or side length: 5.0mm~1000mm |
| Flats |
thickness: 4.0mm~1000mm width: 300mm~2200mm |
| Produce as other form and size according to technical requirements are available. | |
