Monel K500 Tube Sheet
Monel 400's chemistry with aluminum and titanium added for age-hardening — roughly three times the yield strength of standard 400, for services that need Monel's corrosion resistance and can't accept 400's relatively low strength.
Chemical Composition
| Element | Min % | Max % |
|---|---|---|
| Nickel (Ni) | 63.0 | 70.0 |
| Copper (Cu) | 27.0 | 33.0 |
| Aluminum (Al) | 2.30 | 3.15 |
| Titanium (Ti) | 0.35 | 0.85 |
Mechanical Properties (Age-Hardened)
| Property | Typical Value |
|---|---|
| Tensile Strength | 1050 MPa (aged condition) |
| Yield Strength (0.2% offset) | 750 MPa (aged condition) |
| Elongation | 20% min |
| Max. Practical Service Temp. | ~425°C (strength-limited) |
Equivalent Grades
| Standard | Designation |
|---|---|
| ASTM / UNS | N05500 |
| EN / DIN | 2.4375 |
| Trade Name | Monel® K-500 (Special Metals) |
K500 vs. 400 — Which One
See the full Monel 400 datasheet for the standard annealed grade.
Applications
High-strength fasteners and components in the same seawater and sour-service environments as Monel 400, where the added strength allows thinner sections or higher mechanical loading — pump shafts and valve trim are more common than tube sheets, but the alloy is specified where both corrosion resistance and strength are required together.
Advantages & Limitations
Advantages
- ~3x the yield strength of standard Monel 400
- Retains Monel's corrosion resistance profile
- Good resistance to seawater and sour service
Limitations
- Requires precipitation-hardening heat treatment after machining
- Higher cost and longer lead time than Monel 400
- Lower practical temperature ceiling than the annealed grade
FAQ
Usually not — most tube sheet applications are governed by pressure/thickness calculations that standard Monel 400 satisfies without needing K500's extra strength. K500 is reserved for cases with a specific mechanical loading requirement beyond typical pressure-boundary duty.
The corrosion resistance mechanism is largely unaffected by the aging heat treatment, since it comes from the base nickel-copper chemistry rather than the aluminum/titanium precipitates that provide strength.
Yes, particularly in the aged condition — machining is typically done before aging where possible, since the material is softer and easier to work with before the strengthening heat treatment is applied.