COMPREHENSIVE TECHNICAL ANALYSIS AND DATASHEET OF NIMONIC 90 (UNS N07090) FASTENING SYSTEMS
Nimonic 90 (officially designated as UNS N07090) is a precipitation-hardenable nickel-chromium-cobalt superalloy. By integrating significant levels of Cobalt and precisely balanced Titanium and Aluminum, Nimonic 90 offers a substantial performance upgrade over Nimonic 80A. It is engineered for extreme reliability in high-stress environments, providing superior creep-rupture strength and enhanced oxidation resistance at temperatures up to 1680°F (920°C).
The addition of Cobalt stabilizes the austenitic matrix and increases the solvus temperature of the gamma-prime phase, allowing the fastening system to maintain high load-bearing capacity in thermal zones where other superalloys would begin to soften. It is the definitive choice for aerospace turbine blades, high-pressure hot-work tools, and critical nuclear reactor springs that must withstand intense cyclic loading at red-hot temperatures.
■ Product Overview & Specifications
Nimonic 90 fasteners are typically supplied in the solution-treated and aged condition to ensure maximum resistance to creep deformation and fatigue under extreme thermal stress.
| Material Classification | Precipitation-Hardenable Nickel-Chromium-Cobalt Superalloy |
|---|---|
| UNS Designation | N07090 |
| Microstructure | FCC Austenitic matrix with gamma-prime [Ni3(Al, Ti)] precipitates |
| Magnetic State | Non-Magnetic |
| Density | ~8.18 g/cm³ (0.295 lb/in³) |
| Melting Range | 2480°F – 2535°F (1360°C – 1390°C) |
| Size Range | Metric: M4 to M64 | Imperial: #8 to 2-1/2" Custom high-temperature springs and forged bolts available. |
| Thread Types | UNC, UNF, Metric Coarse, Metric Fine (Rolled threads strictly recommended) |
■ Proprietary Datasheet Download (GATED)
Access professional-grade technical data for Nimonic 90, including stress-rupture life charts up to 900°C, thermal fatigue resistance data, and specialized spring relaxation parameters.
Nimonic 90 (N07090) — Complete Technical Datasheet
Contains detailed Larson-Miller creep parameters, specific heat treatment cycles for spring vs. bolt applications, and AMS 5829 specification compliance metrics.
⬇ DOWNLOAD DATASHEET■ MTC Integration Section
To ensure structural integrity in high-load aerospace and power generation applications, Ananka Group provides absolute metallurgical verification for every batch.
- EN 10204 Type 3.1: Detailed reporting of actual ladle chemical analysis (verifying Cobalt, Titanium, and Aluminum), mechanical test results (tensile and hardness), and certified heat treatment logs.
- EN 10204 Type 3.2: Third-party witness testing facilitated for critical aerospace turbine components and offshore high-temperature valving.
■ Chemical Composition (UNS N07090)
The core strength of Nimonic 90 is derived from its Cobalt-Chromium-Nickel base. Cobalt enhances the alloy's ability to maintain high strength at temperatures exceeding 800°C by raising the stability of the reinforcing precipitates.
| Nickel (Ni) | Chromium (Cr) | Cobalt (Co) | Titanium (Ti) | Aluminum (Al) | Iron (Fe) | Carbon (C) |
|---|---|---|---|---|---|---|
| Balance (~54 - 58%) | 18.0 – 21.0 | 15.0 – 21.0 | 2.00 – 3.00 | 1.00 – 2.00 | 1.50 Max | 0.13 Max |
*Manganese and Silicon are capped at 1.00% Max. Small additions of Boron (0.02 Max) and Zirconium (0.15 Max) are often utilized to improve high-temperature grain boundary strength.
■ Mechanical Properties & High-Temp Integrity
Nimonic 90 provides a formidable combination of high tensile strength and ductility. Its mechanical properties remain stable through extensive thermal cycling, making it one of the most reliable superalloys for high-temperature springs.
| Property | Room Temperature (Aged) | At 1470°F (800°C) |
|---|---|---|
| Tensile Strength (Min) | 1150 MPa (167 ksi) | ~800 MPa (116 ksi) |
| Yield Strength (0.2% Offset, Min) | 750 MPa (109 ksi) | ~600 MPa (87 ksi) |
| Elongation in 2" (Min) | 20% | ~15% |
| Hardness | 250 to 350 HBW | N/A |
■ Equivalent Grades & Designations
| Standard / System | Designation |
|---|---|
| UNS Designation | N07090 |
| Common Trade Name | Nimonic 90®, Alloy 90 |
| European Equivalent | W.Nr. 2.4632 / NiCr20Co18Ti |
| Aerospace Specs | AMS 5829, BS HR2, HR202 |
■ Applications & Industries
Nimonic 90 is selected when the thermal-mechanical stress exceeds the capabilities of standard Nimonic 80A or Inconel 718, particularly in spring applications.
- Aerospace Propulsion: Fastening systems for turbine disks, nozzle guide vanes, and high-temperature engine springs.
- High-Temperature Springs: Valve springs for heavy-duty marine diesel engines and critical load-bearing springs in nuclear reactor cores.
- Industrial Tooling: High-stress components for hot-work tools, extrusion dies, and die-casting inserts.
- Automotive: Turbocharger hardware and exhaust manifold fasteners for high-performance racing engines.
■ Compatible Fastener Assemblies
Because Nimonic 90 is often used in dynamic spring and bolt applications, mating with compatible superalloys is critical to prevent joint relaxation and thread galling.
| Fastener (Nimonic 90 Bolts/Studs) | Recommended Mating Component (Nuts) |
|---|---|
| Nimonic 90 (Aged Condition) | Nimonic 90 Heavy Hex Nuts (Requires specialized high-temp lubrication) |
| Nimonic 90 (Aged Condition) | Waspaloy or Inconel 718 Nuts (Optimal for aerospace turbine packages) |
■ Torque & Installation Guidelines
Nimonic 90's high strength allows for significant clamping force. However, at the extreme temperatures where this alloy operates, ceramic-based or high-purity nickel anti-seize is strictly required to prevent thread cold-welding.
| Nominal Diameter | Threads Per Inch (UNC) | Target Torque — Lubricated (ft-lbs) |
|---|---|---|
| 3/8" | 16 | 30 - 40 |
| 1/2" | 13 | 65 - 80 |
| 5/8" | 11 | 135 - 165 |
| 3/4" | 10 | 245 - 285 |
■ Why Choose Ananka Group?
Ananka Group delivers precision-engineered Nimonic 90 solutions, combining expert thermal processing with advanced manufacturing protocols.
- Precision Spring Manufacturing: We specialize in custom-coiled high-temperature Nimonic 90 springs, ensuring the exact aging cycle to achieve maximum fatigue life.
- Advanced CNC Machining: Superalloys like Nimonic 90 work-harden rapidly. Our tooling and feed rates are optimized to prevent surface stress and ensure flawless thread integrity.
- Rolled Thread Excellence: For fasteners subject to cyclic thermal loads, we utilize thread rolling to introduce beneficial compressive stresses into the thread root.
- Absolute Traceability: Every component is marked with a heat number and accompanied by a full metallurgical MTC.
■ Frequently Asked Questions
1. What is the role of Cobalt in Nimonic 90?
Cobalt is the key differentiator between Nimonic 80A and Nimonic 90. It improves the high-temperature strength by stabilizing the gamma-prime precipitates and reducing the stacking fault energy, which significantly boosts creep and fatigue resistance above 700°C.
2. Can Nimonic 90 be used for springs?
Yes, Nimonic 90 is one of the world's premier materials for high-temperature springs. It can operate reliably as a spring at temperatures up to 600°C (1110°F) for extended periods without significant loss of spring force (relaxation).
3. Is Nimonic 90 resistant to oxidation?
Yes. The high Chromium and Nickel content provide excellent resistance to oxidation and scaling in air at temperatures up to 920°C (1680°F), making it suitable for gas turbine environments.
4. Does Nimonic 90 require heat treatment?
Yes. To achieve its full strength, Nimonic 90 must undergo a multi-stage heat treatment: Solution treatment (typically at 1080°C) followed by aging (typically at 700°C-750°C) to precipitate the gamma-prime phase that provides the alloy its legendary strength.