In the world of high-performance materials, few alloys can match the outstanding combination of strength, oxidation resistance, and thermal stability offered by INCONEL 617. This nickel-based superalloy has become a preferred material for demanding applications in aerospace, power generation, and chemical processing industries.
In this article, SASAALLOY provides a comprehensive overview of INCONEL 617, including its composition, mechanical properties, advantages, and typical industrial applications. Whether you are designing components for turbines, heat exchangers, or reformers, understanding INCONEL 617’s properties will help you make informed material selection decisions.
1. Introduction to INCONEL 617
INCONEL 617 is a solid-solution strengthened nickel-chromium-cobalt-molybdenum alloy developed for exceptional performance at high temperatures. It is known for its excellent oxidation resistance, superior creep strength, and outstanding metallurgical stability in environments exceeding 1000°C.
This alloy retains its strength and integrity in aggressive environments containing oxidation, carburization, and hot corrosion—conditions that would quickly degrade most conventional alloys.
Common Designations
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INCONEL Alloy 617
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UNS N06617
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W.Nr. 2.4663
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Alloy 617 / Haynes 617 equivalent
The alloy’s balance of nickel, chromium, cobalt, and molybdenum gives it an unparalleled combination of high-temperature mechanical strength and resistance to chemical attack.
2. Chemical Composition of INCONEL 617
The chemical makeup of INCONEL 617 is carefully engineered to ensure stability, corrosion resistance, and high-temperature performance.
| Element | Content (%) | Function |
|---|---|---|
| Nickel (Ni) | Balance (≥ 44.5) | Provides corrosion and oxidation resistance |
| Chromium (Cr) | 20.0 – 24.0 | Improves oxidation and scaling resistance |
| Cobalt (Co) | 10.0 – 15.0 | Enhances strength and temperature stability |
| Molybdenum (Mo) | 8.0 – 10.0 | Increases creep resistance and solid-solution strengthening |
| Aluminum (Al) | 0.8 – 1.5 | Improves oxidation resistance |
| Carbon (C) | 0.05 – 0.15 | Enhances creep rupture strength |
| Manganese (Mn) | ≤ 1.0 | Aids deoxidation during melting |
| Silicon (Si) | ≤ 1.0 | Enhances oxidation resistance |
| Iron (Fe) | ≤ 3.0 | Minor residual |
| Titanium (Ti) | ≤ 0.6 | Improves structural stability |
The combination of chromium and aluminum provides oxidation resistance, while molybdenum and cobalt reinforce mechanical strength even in extreme temperatures.
3. Mechanical Properties of INCONEL 617
INCONEL 617 offers excellent mechanical properties across a wide temperature range.
| Property | Typical Value |
|---|---|
| Density | 8.36 g/cm³ |
| Tensile Strength (Room Temp) | 890 MPa |
| Yield Strength (0.2% offset) | 440 MPa |
| Elongation | 45% |
| Hardness (Brinell) | ~170 HB |
| Melting Range | 1330–1380°C |
| Creep Rupture Strength (1000°C / 100 hr) | 100 MPa |
These properties make INCONEL 617 suitable for components that must withstand both mechanical stress and extreme heat without significant deformation or oxidation.
4. Key Characteristics and Advantages
1. Exceptional High-Temperature Strength
INCONEL 617 maintains its mechanical strength beyond 1000°C, far exceeding the limits of conventional stainless steels and nickel alloys. This makes it ideal for turbine, furnace, and heat exchanger components.
2. Superior Oxidation and Scaling Resistance
The chromium and aluminum content forms a protective oxide layer on the alloy surface, preventing oxidation and scaling even after long-term exposure to hot air or gas environments.
3. Excellent Creep and Fatigue Resistance
Thanks to the solid-solution strengthening effects of molybdenum and cobalt, INCONEL 617 resists creep and fatigue deformation during prolonged high-temperature operation.
4. Outstanding Metallurgical Stability
Unlike precipitation-hardened alloys, INCONEL 617 remains stable under extended exposure to heat, avoiding grain coarsening or phase transformation that could compromise performance.
5. Good Fabricability
Despite its strength, INCONEL 617 can be welded, formed, and machined using standard nickel-alloy techniques. It can be used for complex parts without sacrificing mechanical integrity.
5. Heat Treatment and Processing
Solution Annealing
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Temperature: 1175–1205°C
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Cooling: Rapid air or water quenching
This process ensures maximum ductility and corrosion resistance before forming or welding.
Welding
INCONEL 617 can be welded using gas tungsten arc (GTAW), gas metal arc (GMAW), or shielded metal arc (SMAW) techniques. Matching filler metal (INCONEL 617 or 625) is recommended for strength and corrosion resistance.
Forming and Machining
INCONEL 617 can be hot-formed between 900–1200°C and cold-formed using conventional methods. Machining requires rigid setups and slower cutting speeds due to its work-hardening nature.
6. Corrosion and Oxidation Resistance
INCONEL 617 performs exceptionally well in both oxidizing and reducing environments.
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Oxidation: Forms a stable chromium-aluminum oxide layer that protects against scaling up to 1100°C.
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Carburization: Resists carbon absorption in high-temperature gas mixtures, preventing embrittlement.
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Sulfur and Chlorine Resistance: Provides reliable performance in combustion gases containing sulfur compounds or chlorides.
This combination of corrosion resistance makes INCONEL 617 a preferred material for gas turbine combustors, reformers, and chemical processing heaters.
7. Applications of INCONEL 617
INCONEL 617 is used in a wide variety of industries where materials are exposed to high temperatures and corrosive environments.
1. Power Generation
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Gas turbine combustion cans
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Transition ducts and liners
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Recuperators and heat exchangers
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Superheater tubes in advanced power plants
2. Chemical and Petrochemical Processing
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Steam reformer tubes and manifolds
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Catalyst support grids
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Furnace retorts and radiant tubes
3. Aerospace and Aviation
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Turbine exhaust casings
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Jet engine combustors
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Transition ducts in gas turbines
4. Nuclear and Hydrogen Production Systems
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Heat exchanger components in next-generation nuclear reactors
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High-temperature hydrogen reformers and separators
5. Industrial Heating Systems
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Burner nozzles
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Furnace liners
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Hot gas conduits and radiant tubes
Its ability to retain strength and resist corrosion in aggressive atmospheres makes INCONEL 617 one of the most trusted materials for long-term high-temperature service.
8. Comparison: INCONEL 617 vs Other Nickel Alloys
| Property | INCONEL 617 | INCONEL 625 | INCONEL 718 |
|---|---|---|---|
| Alloy Type | Solid-solution strengthened | Solid-solution strengthened | Precipitation-hardened |
| Max Operating Temp | 1100°C | 980°C | 700°C |
| Oxidation Resistance | Excellent | Excellent | Good |
| Creep Resistance | Excellent | Moderate | High (below 700°C) |
| Strength at High Temp | Outstanding | Very Good | Limited |
| Typical Use | Turbines, reformers | Chemical plants | Aerospace fasteners |
Conclusion:
While INCONEL 625 and 718 are excellent in moderate heat, INCONEL 617 provides the best combination of high-temperature strength and oxidation resistance, making it superior for continuous service above 1000°C.
9. Fabrication and Welding Guidelines
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Preheat: Not generally required.
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Post-weld Heat Treatment: Usually unnecessary due to solid-solution structure.
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Weld Filler: INCONEL 617 welding electrode or wire recommended.
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Machining Tip: Use sharp carbide tools, heavy cuts, and low speed to minimize work hardening.
INCONEL 617’s weldability and mechanical integrity after fabrication make it suitable for large welded assemblies and complex structures in turbines and heat exchangers.
10. Standards and Specifications
INCONEL 617 conforms to the following international standards:
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ASTM B166 – Rods, bars, and wires
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ASTM B167 / B168 – Seamless tubes, pipes, and plates
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ASTM B564 – Forgings and flanges
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ASME SB-166 / SB-167 / SB-564 – Boiler and pressure vessel use
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EN 10204 3.1 / 3.2 – Certified mill test documentation
All materials supplied by SASAALLOY meet these standards, ensuring traceability and reliability for critical engineering applications.
11. Advantages of Using INCONEL 617
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Extended Service Life – Excellent oxidation and corrosion resistance reduce downtime and replacement frequency.
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High Structural Stability – Resists phase transformation and grain growth under heat.
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Design Flexibility – Easy to form and weld into complex components.
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Superior Strength Retention – Maintains load-bearing capability at extreme temperatures.
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Versatile Applications – Suitable for turbines, furnaces, and reformers alike.
These benefits directly translate into lower maintenance costs, improved operational safety, and higher system reliability.
12. Why Choose SASAALLOY for INCONEL 617
SASAALLOY is a professional supplier and manufacturer of high-performance nickel-based alloys, offering a complete range of INCONEL 617 products in bars, plates, pipes, and forgings.
Advantages of SASAALLOY
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Strict Quality Control: All materials supplied with EN 10204 3.1 / 3.2 certificates.
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Extensive Stock Range: Ready inventory for fast delivery.
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Precision Processing: Cutting, machining, and surface finishing available.
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Competitive Pricing: Factory-direct supply ensures cost efficiency.
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Global Experience: Trusted by clients in more than 40 countries across power, aerospace, and chemical industries.
With a strong technical background and commitment to material excellence, SASAALLOY ensures that every INCONEL 617 product delivers long-term reliability in extreme conditions.
13. Summary of Key Properties
| Feature | Performance |
|---|---|
| Alloy Type | Nickel-Chromium-Cobalt-Molybdenum |
| Temperature Range | Up to 1100°C |
| Strength | High tensile and creep strength |
| Corrosion Resistance | Excellent in oxidizing and carburizing environments |
| Fabrication | Weldable, machinable, and formable |
| Typical Applications | Gas turbines, reformers, heat exchangers, furnaces |
| Supplier | SASAALLOY |
14. Conclusion
INCONEL 617 stands as one of the most advanced high-temperature alloys available today. Its exceptional mechanical strength, oxidation resistance, and metallurgical stability make it the material of choice for gas turbines, reformers, and power generation systems operating at extreme temperatures.
When reliability, longevity, and performance matter, SASAALLOY provides high-quality INCONEL 617 products that meet international standards and customer-specific requirements. With precise processing, strict quality assurance, and global service, SASAALLOY ensures that your projects benefit from the best in nickel-based alloy technology.
Post time: Oct-28-2025