Ni-Cu 400 (Monel®) (UNS N04400)
Description
Alloy 400 (Monel®) is a ductile nickel-copper alloy with resistance to a variety of corrosive conditions. The alloy is most frequently applied in a range of environments ranging from mildly oxidizing through neutral and to moderately reducing conditions. An additional application area of the material is in marine environments and other non-oxidizing chloride solutions.
The alloy has a long history of use as a corrosion resistant material, dating back to the early twentieth century when it was developed as an attempt to use a high copper content nickel ore. The nickel and copper contents of the ore were in the approximate ratio which is now formally specified for the alloy.
As with commercially pure nickel, Alloy 400 is low in strength in the annealed condition. For this reason, a variety of tempers are used which have the effect of increasing the strength level of the material.
Chemical Composition
Chemical Composition (wt%) limits as specified in ASTM B164*
| Carbon | 0.3 | Manganese | 2.0 |
| Nickel | 63.0 min | Silicon | 0.5 |
| Copper | 28.0-34.0 | Sulfur | 0.03 |
| Iron | 2.5 |
*Maximum, unless range is indicated
Physical Properties
Physical properties for Alloy 400
| Density, lb/in3 | 0.319 |
| Modulus of Elasticity, psi | 26 x 106 |
| Coefficient of Thermal Expansion, 68-212˚F, /˚F | 7.7 x 10-6 |
| Thermal Conductivity, Btu/ft hr ˚F | 14 |
| Specific Heat, Btu/lb ˚F | 0.10 |
| Electrical Resistivity, Microhm-in | 20.0 |
Mechanical Properties
Mechanical property requirements as specified for annealed product in ASTM B 164
| Yield Strength, min. (ksi) | 25 |
| Tensile Strength, min. (ksi) | 70 |
| Elongation, min. (%) | 35 |
Standards
Typical standards for Alloy 400
| ASTM B164 |
| ASME SB614 |