In high-temperature engineering, creep-the slow, permanent deformation of materials under mechanical stress-is an invisible enemy. Our Nimonic 75 and 80A high-temperature alloys are designed to overcome this phenomenon. Nimonic 75 is an industry-leading oxidation-resistant alloy, while Nimonic 80A provides superior creep rupture strength for high-temperature fasteners and exhaust valves operating at 700°C to 800°C. As a leading manufacturer of nickel alloys, Gnee Steel can provide you with stability data exceeding 1000 hours for your critical components.
Contact our professionals to recommend alloys suitable for your project
Thermal properties and creep strength information for Nimonic 75 and 80A high-temperature alloys
Thermal properties and creep strength information for Nimonic 75 and 80A high-temperature alloys
Nimonic 75 and Nimonic 80A are nickel-chromium-based superalloys designed for high-temperature environments. Nimonic 75, due to its excellent oxidation resistance and moderate strength, is commonly used in sheet metal manufacturing; while Nimonic 80A is a precipitation-hardening alloy used in applications requiring high creep strength, such as turbine blades.
What is NIMONIC 75 material?
NIMONIC 75 alloy is an 80/20 nickel-chromium alloy with added titanium and carbon. This alloy was originally introduced in the 1940s for the manufacture of turbine blades. It is easy to machine and weld, and possesses good corrosion resistance, mechanical properties, and heat resistance.
1. Comparison of Nimonic 75 and Nimonic 80A Strengthening
Nimonic 75 (GH3030/E1435): Solid solution strengthening. It relies on a stable matrix to resist oxidation. Best suited for parts with low mechanical loads but high heat exposure.
Nimonic 80A (GH4080A/E1437): Precipitation strengthening. The addition of aluminum (A) and titanium (T) forms a submicroscopic γ' phase, which hinders dislocation movement and prevents creep at 800°C.
2. Chemical Composition: Nimonic 75 vs Nimonic 80A
| Element | Nimonic 75 Content (%) | Nimonic 80A Content (%) |
|---|---|---|
| Nickel (Ni) | Balance (≥ 73.0) | Balance (≥ 65.0) |
| Chromium (Cr) | 18.0 – 21.0 | 18.0 – 21.0 |
| Titanium (Ti) | 0.2 – 0.6 | 1.8 – 2.7 |
| Aluminum (Al) | 0.1 – 0.2 | 1.0 – 1.8 |
| Carbon (C) | 0.08 – 0.15 | 0.10 max |
| Silicon (Si) | ≤ 1.0 | ≤ 1.0 |
| Manganese (Mn) | ≤ 1.0 | ≤ 1.0 |
| Iron (Fe) | ≤ 5.0 | ≤ 3.0 |
| Copper (Cu) | ≤ 0.5 | ≤ 0.2 |
| Sulfur (S) | ≤ 0.015 | ≤ 0.015 |
| Cobalt (Co) | – | ≤ 2.0 |
| Boron (B) | – | ≤ 0.008 |
| Zirconium (Zr) | – | ≤ 0.15 |
3. Mechanical Properties: Nimonic 75 vs Nimonic 80A
| Property | Nimonic 75 (Annealed) | Nimonic 80A (Solution Treated + Aged) |
|---|---|---|
| Tensile Strength, Ultimate (Room Temp) | 650 – 750 MPa | 1000 – 1250 MPa |
| Tensile Strength, Yield (0.2% Offset) (Room Temp) | 300 – 450 MPa | 620 – 850 MPa |
| Elongation at Break (Room Temp) | 30 – 40% | 20 – 30% |
| Hardness, Rockwell C (HRC) | 15 – 25 | 28 – 38 |
| Hardness, Brinell (HB) | 150 – 200 | 280 – 350 |
| Modulus of Elasticity (Young's Modulus) | 211 GPa | 211 GPa |
| Poisson's Ratio | 0.30 | 0.30 |
| Impact Strength (Charpy V‑notch, Room Temp) | ~100 – 150 J | ~40 – 80 J |
Click to download the GH3030 alloy PDF file now
4. Nimonic 75 Alloy (UNS N06075)
Thermal Properties:
Melting Point Range: 1340-1380°C.
Thermal Conductivity: 16.7 W/m·°C at 20°C, increasing to 28.0 W/m·°C at 1000°C.
Average Coefficient of Linear Expansion: 12.3 m/m·°C (20-100°C) to 15.5 m/m·°C (20-900°C).
Maximum Operating Temperature: Up to 1100°C (Excellent anti-scaling properties).
Creep and Mechanical Properties:
Tensive Strength: Approximately 750 MPa at room temperature.
Yield Strength: Approximately 350 MPa at room temperature.
Creep Resistance: Primarily for applications requiring moderate strength to be maintained at higher operating temperatures (e.g., combustion chambers).
Key characteristics: Excellent formability and weldability; typically used in the annealed state.
Nimonic 75 Vs Nimonic 80A
5. Nimonic 80A (UNS NO7080)
Thermal Properties:
Melting Point Range: 1320-1365°C
Density: 8.19 g/cm³
Thermal Conductivity: Approximately 11.2 W/m·°C at 20°C, increasing to approximately 25.0 W/m·°C at 800°C
Average Coefficient of Linear Expansion: 12.0 μm/m·°C (20-100°C) to 15.0 μm/m·°C (20-800°C)
Maximum Service Temperature: Up to 815°C for long-term use (higher temperatures for short-term use)
Creep and Mechanical Properties:
Tensive Strength: 900-1000 MPa (room temperature)
Yield Strength: 550-650 MPa (room temperature)
* Creep Strength: Excellent creep resistance at 815°C. Designed for high-stress applications.
Main characteristics: precipitation hardening (typically 8 hours at 1080°C + 16 hours at 700°C).
6. Gnee Steel High-Temperature Alloy Manufacturing Process
Switch to our Nimonic 80A alloy, smelted using the VIM + ESR process.
Triple Smelting Advantages: Through vacuum induction melting and electroslag remelting, we eliminate trace impurities (S, P, Pb) that cause grain boundary slippage.
Proven Stability: Our materials are laboratory tested and maintain a stable microstructure after more than 1000 hours of continuous loading, ensuring your seals remain tight and valves remain sealed.
MTC 3.1 Traceability: Each shipment includes precise creep rupture test data for that specific heat.
Contact us now to get the latest export price for GH3030 in 2026
FAQ
Q1: Can Nimonic 75 be used for load-bearing bolts at 800°C?
A: No. Nimonic 75 lacks the precipitation-hardening phase required to resist creep under high tension. For bolts, studs, and high-pressure pinsNimonic 80A (GH4080A) is the mandatory choice to ensure safety.
Q2: Does your factory provide creep testing services?
A: Yes. We have an in-house superalloy laboratory capable of performing stress Tupture and creep-deformation tests. If your project requires
specific 500h or 1000h data, we can provide validated reports.
Q3: What is the benefit of the Al+Ti micro-additions in Nimonic 80A?
A: These elements form the phase [Nis (AL, Ti)). This phase is like "internal reinforcing bars" within the atomic structure, making the metalincredibly difficult to deform even as it glows red at 800°C.