In aerospace propulsion systems, material failure is not merely a delay, but a critical risk to mission success or failure. For engineers and maintenance, repair, and overhaul (MRO) specialists, thermal fatigue is a major pain point for engine exhaust systems and manifolds.
Our aerospace-grade Inconel 625 alloy, specially designed by Gnee Alloy, effectively addresses these risks. As a Tier 1 supplier, Gnee Alloy provides materials that maintain exceptional structural integrity even under extreme and fluctuating thermal stresses.
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Inconel 625 alloy properties for aerospace engineering
Inconel 625 alloy properties for aerospace engineering
Inconel 625 is a premium nickel-chromium superalloy favored in aerospace engineering for its exceptional high-temperature strength, resistance to thermal fatigue, and outstanding corrosion resistance. Its unique chemical matrix allows for reliable operation across a temperature range from low temperatures to 982°C without the need for complex age-hardening treatments.
What are the main characteristics of Inconel 625?
Inconel 625 alloy is ideal for seawater applications because it possesses the following properties: resistance to localized corrosion (pitting and crevice corrosion), high corrosion fatigue strength, high tensile strength, and resistance to chloride stress corrosion cracking.
1. Material Overview of Inconel 625 Alloy in Aerospace Applications
| Parameter | Description |
|---|---|
| Material | Inconel 625 (UNS N06625) |
| Chinese Equivalent | GH3625 |
| Material Type | Wrought Nickel-based Corrosion Resistant Superalloy |
| Strengthening Mechanism | Solid-solution strengthening (Mo + Nb) |
| Product Forms | Bar, plate, tube, strip, wire, forging |
| Typical Aerospace Applications | Engine exhaust systems, hydraulic lines, fuel systems, heat exchangers, springs, seals |
| Maximum Service Temperature (Load-Bearing) | ~600°C |
| Maximum Service Temperature (Oxidation) | ~980°C |
| Delivery Condition | Solution treated (annealed) – not age-hardenable |
2. Chemical composition of Inconel 625 alloy in aerospace applications (wt%)
| Element | Content (%) | Function |
|---|---|---|
| Nickel (Ni) | ≥ 58.0 (Balance) | Matrix element; high-temperature stability and corrosion resistance |
| Chromium (Cr) | 20.0 – 23.0 | Oxidation and corrosion resistance |
| Molybdenum (Mo) | 8.0 – 10.0 | Core solid-solution strengthening; pitting and crevice corrosion resistance |
| Niobium (Nb) | 3.15 – 4.15 | Solid-solution strengthening; carbide stabilizer |
| Iron (Fe) | ≤ 5.0 | Residual element |
| Titanium (Ti) | ≤ 0.40 | Supplementary strengthening |
| Aluminum (Al) | ≤ 0.40 | Supplementary strengthening |
| Carbon (C) | ≤ 0.10 | Low carbon for weldability and toughness |
| Manganese (Mn) | ≤ 0.50 | Deoxidizer |
| Silicon (Si) | ≤ 0.50 | Deoxidizer |
| Phosphorus (P) | ≤ 0.015 | Ensures toughness |
| Sulfur (S) | ≤ 0.015 | Ensures hot workability |
| Cobalt (Co) | ≤ 1.0 | Residual element |
3. High-temperature mechanical properties of Inconel 625 alloy in aerospace applications
| Temp (°C) | Temp (°F) | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Strength Retention (%) | Aerospace Application |
|---|---|---|---|---|---|---|
| 20 (RT) | 68 | ≥ 830 | ≥ 415 | ≥ 30 | 100 | Ground handling |
| 300 | 572 | ~750 | ~380 | ~35 | 90 | Hydraulic systems |
| 400 | 752 | ~720 | ~370 | ~38 | 87 | Exhaust systems |
| 500 | 932 | ~680 | ~360 | ~40 | 82 | Engine casings |
| 550 | 1022 | ~650 | ~350 | ~42 | 78 | Fuel systems |
| 600 | 1112 | ~600 | ~330 | ~45 | 72 | Peak operating temp |
| 650 | 1202 | ~550 | ~300 | ~48 | 66 | Short-term only |
| 700 | 1292 | ~500 | ~270 | ~50 | 60 | Limited exposure |
| 800 | 1472 | ~400 | ~220 | ~55 | 48 | Not recommended |
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4. inconel 625 Dimensional Specifications
Alloy 625 Bar Products
| Diameter (mm) | Length (mm) | Tolerance | Surface |
|---|---|---|---|
| 6 – 25 | 2000 – 6000 | h6 – h8 | Ground / Bright |
| 25 – 50 | 2000 – 6000 | h6 – h8 | Ground / Bright |
| 50 – 100 | 2000 – 4000 | h7 – h9 | Black / Rough Turned |
| 100 – 200 | 1000 – 3000 | h8 – h10 | Black / Rough Turned |
inconel 625 Tube Products
| OD (mm) | Wall Thickness (mm) | Tolerance | Surface |
|---|---|---|---|
| 6 – 30 | 0.5 – 3.0 | ±0.05 – ±0.10 mm | BA / AP |
| 30 – 50 | 1.0 – 5.0 | ±0.10 – ±0.15 mm | BA / AP |
| 50 – 100 | 2.0 – 8.0 | ±0.15 – ±0.30 mm | BA / AP |
625 Plate Products
| Thickness (mm) | Width (mm) | Length (mm) | Tolerance |
|---|---|---|---|
| 0.5 – 4.0 | 500 – 1200 | 1000 – 3000 | ±5% – ±10% |
| 4.0 – 10.0 | 500 – 1500 | 1000 – 4000 | ±5% – ±10% |
| 10.0 – 25.0 | 500 – 1500 | 1000 – 4000 | ±5% – ±10% |
Contact us to customize Inconel 625 products to fit your project dimensions
5. Non-destructive testing (NDT) of aerospace-grade 625 alloy
| Test Method | Requirement | Standard | Acceptance Criteria |
|---|---|---|---|
| Ultrasonic Testing (UT) | 100% (bars ≥ 12mm) | ASTM E2375 / AMS 2370 | No defects exceeding 0.8mm |
| Eddy Current Testing (ET) | 100% (tubes) | ASTM E426 | No relevant indications |
| Liquid Penetrant Inspection (LPI) | As specified | ASTM E1417 | No relevant indications |
| Visual Inspection | 100% | - | No surface defects |
| Hydrostatic Test | 100% (tubes/pressure parts) | ASME Section VIII | No leakage |
6. Applications of Inconel 625 alloy in the aerospace industry
Stop the cycle of maintenance and replacement in these critical areas:
Engine Exhaust Systems: Resisting hot gas erosion and scaling.
Fuel & Hydraulic Manifolds: Maintaining high-pressure integrity in fluctuating heat.
Turbine Shroud Rings: Stable dimensional control at operating temperatures.
Afterburner Components: Survive in the most intense thermal cycling zones.
Why source from Gnee Alloy's wholesale inventory?
✅️Direct Factory Price: Eliminate middleman markups and secure the best rates for bulk aviation projects.
✅️MTC 3.1 Traceability: Full heat-analysis and mechanical verification certificates included with every shipment.
✅️Wholesale Inventory: Large stock of standard thicknesses and diameters ready for Fast Global Shipping.
✅️Custom Fabrication: We offer precision laser cutting and bending to provide "Ready-to-Assemble" components based on your blueprints.
Gnee Alloy 625 Alloy certificate
Gnee Alloy Product Packaging
All stainless steel products are:
✅️Packed in wooden pallets or crates
✅️Covered with moisture-proof wrapping
✅️Labeled with heat number, standard, and size
✅️Shipped worldwide via sea, air, or express
Gnee Alloy 625 Alloy Packaging
Gnee Alloy Production Equipment and Product Testing
Contact us now to get the latest export price for Inconel 625 in 2026
Contact us for a quote on high-performance 625 Alloy!
Stop paying exorbitant prices for Western brands. We can offer you the same aerospace-grade 625 superalloy tubing at a lower price. Our team is ready to provide you with a rapid quote (RFQ) within 12 hours.
Email: [ru@gneesteelgroup.com]
WhatsApp/WeChat: +86 15824687445
Website: [https://www.china-plate-steel.com/]
FAQ
Q1: Why is Inconel 625 better than 310S for engine manifolds?
A: While 310S resists heat, it is prone to scaling and has poor thermal fatigue strength. Inconel 625 forms a tightly adherent oxide layer and its Nickel-Chromium-Molybdenum matrix resists the cracking caused by constant thermal expansion and contraction.
Q2: Can you provide Alloy 625 tubing compliant with AMS 5581?
A: Yes. We specialize in both seamless and welded tubing that meets AMS 5581 requirements, specifically optimized for high-pressure aerospace gas transport.
Q3: Does Inconel 625 require post-weld heat treatment?
A: Generally, No. Inconel 625 is a solid-solution alloy and is used in the as-welded condition. This is a massive Cost-effective Solution as it reduces assembly time and prevents distortion from secondary aging cycles.
Q4: Do you offer trial orders for aircraft prototype development?
A: Absolutely. We support aerospace innovation with Flexible MOQs on our standard stock to help your R&D phase reach certification faster.