UNS N04400 Corrosion-Resisting Superalloy Bars and Plates
This nickel-copper solid-solution corrosion-resistant alloy is based on nickel-copper matrix. It features outstanding resistance to hydrofluoric acid, seawater, alkaline liquor and neutral chloride corrosion. Free from age hardening, it owns excellent hot/cold workability and weldability, stable low-temperature microstructure and good stress corrosion cracking resistance, suitable for pressure-bearing service under mild-to-moderate corrosive environments.
Applications of UNS N04400
Widely used in hydrofluoric acid reactors, pickling equipment, seawater desalination heat exchange tubes, marine seawater pipelines, oil & gas gathering pipelines, valves & pump bodies, salt-making equipment and alkaline chemical heat exchangers. It is the core pressure-bearing material for service exposed to hydrofluoric acid and seawater corrosion.
Equivalent Grades and Commonly Used Specifications of UNS N04400
| Steel Grade | Specification | Specification Name |
| NS6400/NW4400 | GB/T 26030 | Nickel and nickel alloys forgings |
| GB/T 21653 | Nickel and nickel-alloy wire and drawing stock | |
| GB/T 15007 | Designations of corrosion-resisting alloy | |
| GB/T 15008 | Wrought corrosion-resistant alloy bars | |
| UNS N04400 | ASTM B127 | Standard Specification for Nickel-Copper Alloy Plate, Sheet, and Strip |
| ASTM B564 | Standard Specification for Nickel Alloy Forgings | |
| ASTM B164 | Standard Specification for Nickel-Copper Alloy Rod, Bar, and Wire | |
| ASTM B165 | Standard Specification for Seamless Nickel-Copper 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 N04400
|
Elements |
Ni | Cu | Fe | Mn | C | Si |
S |
|
Mass Fraction% |
≥63.00 | 28.00~34.00 | ≤2.50 | ≤2.00 | ≤0.30 | ≤0.50 |
≤0.024 |
| Products produced as per other specifications or technical agreements (if need) are available. | |||||||
Typical Heat Treatment Condition and Mechanical Properties of UNS N04400
|
Delivery Condition |
Mechanical Properties and Hardness of Heat-Treated Specimens | ||||||
| Rp0.2/(N/mm2) | Rm/(N/mm2) | A/% | Zb/% | Aku2d/J | HBW |
HRC |
|
|
Hot-worked(Annealed) or Cold-worked(Annealed) |
≥170 | ≥480 | ≥35 | / | / | / |
/ |
| Products produced as per other specifications or technical agreements (if need) are available. | |||||||
Product Forms and Size Range of UNS N04400
|
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. | |






