Corrosion Resistant Alloys
NAS NW400 (UNS N04400), comparable to Monel® 400 Alloy
An alloy including copper and nickel, NAS NW400 (NW 4400, UNS N04400), comparable to Monel® 400 Alloy, shares in the noble properties of copper and passivation of nickel to provide excellent corrosion resistance. It is therefore used in seawater desalination systems, heat exchangers and marine structure jackets. Nippon Yakin supplies this product in plate, sheet and strip forms.
Coil
Sheet
Plate
Chemical Composition
NW 4400
| C | Si | Mn | S | Ni | Cu | Fe | |
|---|---|---|---|---|---|---|---|
| Min | ― | ― | ― | ― | 63.0 | 28.0 | ― |
| Max | 0.30 | 0.5 | 2.0 | 0.025 | ― | 34.0 | 2.5 |
UNS N04400
| C | Si | Mn | S | Ni | Cu | Fe | |
|---|---|---|---|---|---|---|---|
| Min | ― | ― | ― | ― | 63.0 | 28.0 | ― |
| Max | 0.3 | 0.5 | 2.0 | 0.024 | ― | 34.0 | 2.5 |
Physical Properties
| Specific heat (J/kg･K) | 20℃ | 427 |
| Specific resistivity (μΩ･cm) | 54.7 | |
| Thermal conductivity (W/m･K) | 21.8 | |
| Coefficient of thermal expansion (10-6/℃) | 20–100℃ | 13.9 |
| Melting point (℃) | 1300-1350 | |
Mechanical Properties
Mechanical Properties at Room Temperature
NW 4400 Annealing
| 0.2% proof stress (N/mm2) |
Tensile strength (N/mm2) |
Elongation (%) |
Hardness (HV) |
|---|---|---|---|
| ≥ 195 | ≥ 480 | ≥ 35 | ― |
UNS N04400 Annealing Hot-rolled plate
| 0.2% proof stress (N/mm2) |
Tensile strength (N/mm2) |
Elongation (%) |
Hardness (HV) |
|---|---|---|---|
| ≥ 195 | ≥ 485 | ≥ 35 | ― |
UNS N04400 Annealing Cold-rolled sheet
| 0.2% proof stress (N/mm2) |
Tensile strength (N/mm2) |
Elongation (%) |
Hardness (HV) |
|---|---|---|---|
| ≥ 195 | 485-585 | ≥ 35 | ― |
Examples Annealing Hot-rolled plate
| 0.2% proof stress (N/mm2) |
Tensile strength (N/mm2) |
Elongation (%) |
Hardness (HV) |
|
|---|---|---|---|---|
| 12-mm thick | 209 | 513 | 52 | 131 |
Work Hardening Properties
NAS NW400 is far less hard than SUS 301 and SUS 304, making bending and other such processes easy to perform.
Corrosion Resistance
| Type of acid | Test temperature (℃) | Concentration (wt%) | Corrosion rate (mm/y) | |
|---|---|---|---|---|
| NAS NW400 (UNS N04400) |
SUS 316L (UNS S31603) |
|||
| Sulfuric acid | 80 | 5 | 0.28 | 1.67 |
| 10 | 0.27 | 4.69 | ||
| 20 | 0.20 | 71.9 | ||
| 40 | 0.16 | 765 | ||
| 60 | 0.14 | 704 | ||
| 80 | 0.80 | 33.7 | ||
| Boiling | 5 | 0.21 | 8.19 | |
| 10 | 0.36 | 24.6 | ||
| 20 | 0.53 | 179 | ||
| 40 | 2.12 | 3129 | ||
| Hydrochloric acid | 80 | 0.1 | 0.34 | 0.02 |
| 1 | 0.40 | 2.73 | ||
| 2 | 0.46 | 6.75 | ||
| 3 | 0.63 | 14.9 | ||
| Boiling | 0.1 | 0.13 | 0.01 | |
| 1 | 1.37 | 8.86 | ||
| 2 | 3.06 | 27.5 | ||
| 3 | 3.45 | 76.6 | ||
| Fluoric acid | 80 | 0.1 | 0.28 | 0.50 |
| 1 | 0.32 | 14.5 | ||
| 2 | 0.37 | 35.4 | ||
| 3 | 0.35 | 54.1 | ||
| Nitric acid | Boiling | 20 | 4615 | 0.02 |
| 40 | ＞10000 | 0.05 | ||
| 60 | ＞10000 | 0.17 | ||
| Phosphoric acid | Boiling | 20 | 0.24 | 0.04 |
| 40 | 0.16 | 0.25 | ||
| 60 | 0.24 | 0.56 | ||
| 80 | 6.90 | 25.0 | ||
| Formic acid | Boiling | 20 | 0.05 | 0.35 |
| 40 | 0.08 | 0.62 | ||
| 60 | 0.05 | 0.73 | ||
| 80 | 0.02 | 0.49 | ||
| Acetic acid | Boiling | 20 | 0.11 | ＜0.01 |
| 40 | 0.04 | ＜0.01 | ||
| 60 | 0.04 | ＜0.01 | ||
| 80 | 0.05 | ＜0.01 | ||
| 99.7 | 0.01 | ＜0.01 | ||
24-hour immersion test
Weldability
TIG, MIG, shield metal arc and resistance welding can all be used with NAS NW400. For the TIG and MIG consumable, we recommend YNiCu-7.
Heat Treatment
Heat treatment should be carried out between 700 and 900℃, preferably followed by rapid air cooling.
Applications
Marine structure covering; desalination, salt production and oil refining equipment; ship parts; heat exchangers; valves and pump members for chemical and seawater desalination plants.
* Monel is a registered trademark of Special Metals Corporation.
