If you’re working with high-temperature applications like jet engines or gas turbines—where strength and oxidation resistance are non-negotiable—UNS N07040 Nimonique 75 superalloy is a top solution. Cet alliage nickel-chrome-cobalt excelle dans le maintien des performances sous des températures extrêmes, ce qui en fait un incontournable dans les industries aérospatiales et énergétiques. Ce guide détaille ses principales propriétés, utilisations réelles, méthodes de fabrication, and how it compares to other materials—so you can make informed decisions for your high-demand projects.
1. Material Properties of UNS N07040 Nimonic 75 Superalliage
Nimonic 75’s performance stems from its carefully balanced composition and exceptional high-temperature traits. Let’s explore each property clearly.
1.1 Composition chimique
Every element works together to boost strength, oxidation resistance, et stabilité thermique. Below is its typical composition (by weight):
| Élément | Gamme de contenu (%) | Key Role |
|---|---|---|
| Nickel (Dans) | 70–75 | Base metal—provides high-temperature ductility and stability |
| Chrome (Cr) | 18–21 | Enhances oxidation resistance (critical for turbine and engine parts) |
| Cobalt (Co) | 1.0–2.5 | Improves high-temperature strength and creep resistance |
| Molybdène (Mo) | Max 0.5 | Boosts corrosion resistance in mild acidic environments |
| Titane (De) | 0.3–0.8 | Works with aluminum to form strengthening phases (gamma prime) |
| Aluminium (Al) | 0.3–0.8 | Enables age hardening (heat treatment to boost strength) |
| Fer (Fe) | Max 2.0 | Adds minor structural strength without reducing heat resistance |
| Carbone (C) | 0.03–0.10 | Strengthens grain boundaries (prevents cracking at high temps) |
| Manganèse (Mn) | Max 0.5 | Aids in manufacturing (par ex., welding and casting) |
| Silicium (Et) | Max 0.5 | Reduces oxidation at extreme temperatures |
| Soufre (S) | Max 0.015 | Kept low to prevent brittleness in high-heat conditions |
1.2 Propriétés physiques
These traits make Nimonic 75 ideal for high-temperature design and industrial use:
- Densité: 8.1 g/cm³ (heavier than aluminum, lighter than Hastelloy X)
- Point de fusion: 1390–1430°C (2530–2600°F) – handles extreme heat in jet engines and turbines
- Conductivité thermique: 12.5 Avec(m·K) at 20°C (68°F); 21.0 Avec(m·K) at 800°C – efficient heat transfer
- Thermal Expansion Coefficient: 13.0 μm/(m·K) (20–100°C); 17.0 μm/(m·K) (20–800°C) – minimal warping in heat cycles
- Electrical Resistivity: 128 Ω·mm²/m at 20°C – suitable for electrical components in high-heat areas
- Propriétés magnétiques: Slightly magnetic at room temperature (loses magnetism above 450°C/840°F) – works for most industrial needs
1.3 Propriétés mécaniques
Nimonic 75’s strength shines at high temperatures, thanks to age hardening. All values below are for theage-hardened (traité thermiquement) version:
| Propriété | Valeur (Room Temperature) | Value at 800°C |
|---|---|---|
| Résistance à la traction | Min 850 MPa (123 ksi) | 480 MPa (70 ksi) |
| Limite d'élasticité | Min 500 MPa (72 ksi) | 380 MPa (55 ksi) |
| Élongation | Min 25% (dans 50 mm) | 30% (dans 50 mm) |
| Dureté | Min 280 HB (Brinell) | N / A |
| Résistance à la fatigue | 350 MPa (10⁷ cycles) | 200 MPa (10⁷ cycles) |
| Résistance au fluage | Maintains strength up to 850°C (1560°F) – no deformation under long-term heat | – |
1.4 Autres propriétés
- Résistance à la corrosion: Excellent in oxidizing environments (par ex., air, vapeur) and mild acids – outperforms stainless steel at high temps.
- Oxidation Resistance: Resists scaling in air up to 950°C (1740°F) for long periods – ideal for turbine blades and exhaust parts.
- Stress Corrosion Cracking (SCC) Resistance: Resists SCC in chloride-rich solutions (a common issue for 316 acier inoxydable).
- Pitting Resistance: Good resistance to pitting in salty or acidic brines (suitable for marine gas turbines).
- Hot/Cold Working Properties: Easy to hot forge (at 1100–1200°C) – cold working is possible but may require annealing to restore ductility.
2. Applications of UNS N07040 Nimonic 75 Superalliage
Nimonic 75’s high-temperature strength and oxidation resistance make it perfect for demanding industries. Voici ses utilisations les plus courantes, avec des exemples concrets:
2.1 Composants aérospatiaux & Jet Engine Parts
- Use Case: A European aerospace manufacturer uses Nimonic 75 for jet engine turbine blades. The blades handle 800°C temperatures and high rotational stress—they’ve lasted 8000 flight hours, par rapport à 5000 hours for stainless steel blades.
- Other Uses: Combustion chamber liners, engine fasteners, and afterburner parts.
2.2 Gas Turbine Components
- Use Case: A power plant in Saudi Arabia uses Nimonic 75 for industrial gas turbine buckets. The buckets operate at 820°C—they’ve run for 6 years without wear, contre. 3 years for Inconel 600 buckets.
2.3 High-Temperature Furnace Components
- Use Case: A metal processing plant in Germany uses Nimonic 75 for furnace heating elements. The elements operate at 900°C daily—they’ve lasted 5 années, contre. 2 years for Hastelloy C22 elements.
2.4 Missile Components
- Use Case: A defense contractor uses Nimonic 75 for missile engine nozzles. The alloy resists the extreme heat of rocket fuel combustion (up to 1200°C for short bursts), ensuring reliable performance.
2.5 Automotive Turbochargers
- Use Case: A luxury car brand uses Nimonic 75 for high-performance turbocharger rotors. The rotors handle 750°C exhaust heat—they last 3x longer than aluminum rotors and improve fuel efficiency by 10%.
3. Manufacturing Techniques for UNS N07040 Nimonic 75 Superalliage
To maximize Nimonic 75’s performance, manufacturers use specialized methods tailored to its properties:
- Fonderie: Investment casting (using a wax mold) is ideal for complex shapes like turbine blades. The low sulfur content prevents defects during casting.
- Forgeage: Hot forging (at 1100–1200°C) shapes the alloy into strong parts like turbine buckets. Forging improves grain structure, boosting creep resistance.
- Soudage: Gas Tungsten Arc Welding (GTAW) is recommended. Use matching filler metals (par ex., ERNiCrCoMo-1) to maintain strength and corrosion resistance. Pre-weld annealing (at 1050°C) reduces cracking risk.
- Usinage: Use carbide tools with sharp edges. Add coolant (par ex., mineral oil) to prevent overheating—Nimonic 75 work-hardens quickly, so moderate cutting speeds are needed.
- Traitement thermique (Critical for Strength):
- Solution Annealing: Heat to 1050–1100°C, cool rapidly (air or water) – softens the alloy for forming.
- Age Hardening: Heat to 700–750°C for 16–24 hours, cool slowly – forms gamma prime phases to boost strength and creep resistance.
- Traitement de surface: Shot peening (blasting with small metal balls) enhances fatigue resistance. Passivation (using nitric acid) improves pitting resistance—no painting is needed.
4. Étude de cas: Nimonic 75 in Jet Engine Turbine Blades
An aerospace company needed to upgrade turbine blades for a commercial jet engine. The old blades (made of Inconel 600) failed after 5000 flight hours due to creep deformation at 750°C.
They switched to Nimonic 75 blades. Here’s the result:
- Lifespan: The blades have lasted 8000 flight hours with no creep or cracking.
- Économies de coûts: Replacement costs dropped by 40% (fewer frequent blade changes).
- Performance: The blades’ higher strength allowed the engine to run at 50°C hotter, improving thrust by 7% and fuel efficiency by 5%.
This case proves why Nimonic 75 is the top choice for high-stress, high-temperature aerospace parts.
5. Comparative with Other Materials
How does UNS N07040 Nimonic 75 stack up against other common high-temperature materials? The table below compares key properties:
| Matériel | Max Service Temp (°C) | Résistance à la traction (MPa, RT) | Résistance au fluage (800°C) | Coût (Relative) |
|---|---|---|---|---|
| Nimonic 75 | 850 | 850 | Excellent | Haut |
| Acier inoxydable 316 | 870 | 515 | Pauvre | Faible |
| Titanium Alloy Ti-6Al-4V | 400 | 860 | Équitable | Très élevé |
| Inconel 625 | 980 | 930 | Very Good | Haut |
| Hastelloy X | 1090 | 700 | Bien | Haut |
| Monel 400 | 480 | 550 | Pauvre | Moyen |
| Acier au carbone | 425 | 400 | Very Poor | Très faible |
Key Takeaways:
- Nimonic 75 outperforms stainless steel and Monel 400 in high-temperature strength and creep resistance.
- It’s more affordable than titanium alloys and offers better creep resistance than Hastelloy X at 800°C.
- Inconel 625 works at higher temps but is pricier—Nimonic 75 offers better value for applications up to 850°C.
Yigu Technology’s Perspective
Chez Yigu Technologie, we recommend UNS N07040 Nimonic 75 for clients in aerospace, énergie, et la défense. Its exceptional high-temperature strength and oxidation resistance make it a reliable choice for jet engines, turbines à gaz, and turbochargers. Our team provides custom forging, usinage, and heat treatment for Nimonic 75 composants, ensuring they meet strict industry standards. For projects needing long-term durability in extreme heat, Nimonic 75 delivers unmatched value and performance.
FAQ
1. Can UNS N07040 Nimonic 75 handle temperatures above 850°C?
It can handle short bursts of higher temperatures (up to 900°C) but is designed for long-term use at 850°C. Beyond that, oxidation may accelerate—for temps above 900°C, Hastelloy X or Inconel 625 est un meilleur choix.
2. Is Nimonic 75 suitable for marine gas turbines?
Oui! Its goodpitting resistance and saltwater corrosion protection make it ideal for marine gas turbines—outperforming stainless steel and even some Inconel alloys in coastal environments.
3. What’s the typical lifespan of Nimonic 75 parts in jet engines?
In jet engine turbine blades or combustion chambers, Nimonic 75 parts last 8000–10,000 flight hours—1.5–2x longer than Inconel 600 parties. Proper maintenance (like regular inspections) can extend this lifespan even further.