Nickel Alloy / Monel®
Monels® are a Nickel alloy material with addition of:
- Copper (Cu)
- Silicon (Si)
- Manganese
These materials are also known as Monel, Alloy 400 and Alloy K500
Common Material Specifications
Ni Cu30 Fe3.5 Si1.5(+) (Monel 400)
- A494 M-35-1 (UNS N24135) (Low Si –weldable)
- A494 M-35-2 (UNS N04020)
- BS3071: NA1
- BS3071: NA3
OTHERS
- Wrought equivalent Alloy 400 (UNS N04400)
Typical Properties
- Tensile 430 N/mm2
- Yield 170-205 N/mm2
- Elongation 20-25%
- Hardness HB 100-150
- Density 8.8 g/cm3
- Pressure temperature rating: B16.34 Group 3.4 15.9 bar class 150
Corrosion Properties
- Good general corrosion for seawater service
- Especially good for higher flow rates
- Excellent trim material for NAB, gains cathodic protection with many alloys.
- Not recommended for low velocities
Additional Uses & Comments
- Variety of wrought/ bar specifications available, good for trim material. Excellent strength from K500
- Used for oxygen service
- Reasonable castabilty with suitable design and higher Si content
- Weldable with lower Si content
- Excellent for hydrofluoric & other acids (not nitric)
Cautions
- Ease of manufacture: trade-off between castability and weldability
- Pitting can be a problem at low velocities
- Don’t use as trim for austenitic stainless
- P/T rating class 300=600 psi CWP
- Cost effectiveness need consideration
