Table of Contents
Introduction
Inconel X-750 is a versatile and high-performance alloy known for its exceptional strength and durability across extreme temperature ranges. This article provides a comprehensive look into Inconel X750, covering its chemical composition, mechanical and physical properties, heat treatment processes, and corrosion resistance. We’ll explore how Alloy X-750 compares to similar alloys, such as Inconel 718 and Hastelloy X, and examine its advantages and specific applications in demanding industries like aerospace, nuclear energy, and chemical processing.
What is Inconel X-750?
Inconel X-750, also known as UNS N07750, is a precipitation-hardenable nickel-chromium alloy strengthened by aluminum and titanium. It offers high strength and creep-rupture resistance up to 1300°F (700°C) and remains effective in cryogenic conditions. Known for excellent corrosion and oxidation resistance, Inconel X-750 resists industrial corrosives, including chloride stress corrosion cracking. It is widely used in applications such as gas turbines, rocket engines, springs, and fasteners due to its stability across extreme temperatures.
What Are the Specifications of Inconel Alloy X-750?
X-750 Inconel Equivalent
| Specification | Equivalent |
| UNS | N07750 |
| AMS | 5598, 5667, 5698, 5699 |
| ASTM | B637 |
| DIN | W.Nr. 2.4669 |
Inconel X-750 Chemical Composition
| Element | Composition (%) |
| Nickel (Ni) | 70.0 (min) |
| Chromium (Cr) | 14.0-17.0 |
| Iron (Fe) | 5.0-9.0 |
| Titanium (Ti) | 2.25-2.75 |
| Aluminum (Al) | 0.4-1.0 |
| Columbium (Cb) | 0.7-1.2 |
| Manganese (Mn) | 1.0 max |
| Silicon (Si) | 0.5 max |
| Copper (Cu) | 0.5 max |
| Carbon (C) | 0.08 max |
| Sulfur (S) | 0.01 max |
Inconel Metal X-750 Mechanical Properties
| Property | Value |
| Tensile Strength | 130 ksi (min) / 896 MPa (min) |
| Yield Strength (0.2% Offset) | 70 ksi (min) / 482 MPa (min) |
| Elongation | 20% (min) |
| Hardness | 331 HB (max) |
Inconel Metal X-750 Physical Properties
| Property | Value |
| Density | 8.28 g/cm³ |
| Melting Point | 1393-1427°C (2540-2600°F) |
| Specific Heat Capacity | 435 J/kg·K |
| Thermal Conductivity | 11.2 W/m·K at 21°C |
| Electrical Resistivity | 1.29 μΩ·m at 21°C |
Nickel Alloy X-750 Corrosion Resistance
| Environment | Resistance |
| Oxidizing Conditions | Excellent, maintains stability and prevents oxidation up to 1300°F (704°C) |
| Reducing Conditions | High resistance, with good performance under chemical exposure up to 1800°F (982°C) |
| Chloride Stress Cracking | Exceptional resistance in fully age-hardened condition, ideal for chloride-rich environments |
| Industrial Corrosives | Resistant to a wide range of acids, alkalis, and salts in both oxidizing and reducing conditions |
Inconel X-750 Heat Treatment
| Treatment Process | Description |
| Solution Treatment | Heated to 1975°F (1080°C) for 2 hours, followed by air cooling to improve alloy strength |
| Precipitation Hardening | Heated to 1300°F (704°C) for 20 hours, then furnace cooled to enhance creep-rupture strength at elevated temperatures |
| Final Aging | Heated between 1100°F (593°C) and 1350°F (732°C) for 16 hours to achieve optimal mechanical properties and corrosion resistance |
What Are the Advantages of Inconel Alloy X-750?
- High Strength at Elevated Temperatures:Maintains high tensile strength and creep-rupture resistance up to 1300°F (704°C), ensuring structural integrity under extreme heat.
- Exceptional Corrosion and Oxidation Resistance:Exhibits excellent resistance to oxidation and corrosion in both oxidizing and reducing environments, making it suitable for harsh industrial settings.
- Chloride Stress Corrosion Cracking Resistance:In the fully age-hardened condition, Inconel X-750 is highly resistant to chloride stress corrosion cracking, ideal for marine and chemical environments.
- Cryogenic Temperature Stability:Retains toughness and stability even at cryogenic temperatures, enabling its use in a wide temperature range.
- Precipitation-Hardenable Alloy:Enhanced by additions of aluminum and titanium, Inconel X-750 can be strengthened through heat treatment for improved performance.
- Good Workability and Weldability:Allows for easier machining and welding, facilitating use in complex components like springs and fasteners.
What is Inconel X-750 Used For?
- Aerospace Components:Gas turbine blades, jet engine thrust chambers, seals.
- Nuclear Reactors:Springs, bolts, and fasteners within reactor cores.
- Industrial Springs and Fasteners:High-temperature springs, bolts, fasteners for industrial machinery.
- Gas Turbines:Combustors, turbine blades, heat shields.
- Rocket Engines:Thrust chambers, exhaust nozzles.
- Oil and Gas Industry Equipment:Downhole tools, heat exchangers, drilling components.
- Chemical Processing Equipment:Reaction vessels, piping exposed to corrosive chemicals.
How Does Inconel X-750 Compare to Other Alloys?
Inconel x750 vs 718
Inconel X-750 and Inconel 718 are both nickel-chromium superalloys with distinct uses. Inconel 718, with added molybdenum, offers enhanced corrosion resistance and performs well at slightly higher temperatures than Alloy X-750’s limit of 1300°F (704°C). Inconel X750, strengthened with aluminum and titanium, is preferred for high-temperature springs, nuclear reactors, and gas turbines due to its excellent creep resistance.
Inconel X-750 vs. Hastelloy X
Inconel X-750 and Hastelloy X vary mainly in temperature and corrosion resistance. Hastelloy X, a nickel-chromium-molybdenum alloy, withstands higher temperatures beyond 1300°F and offers excellent oxidation resistance. Alloy X-750 excels in high strength and stability, making it suitable for aerospace and nuclear components, while Hastelloy X is ideal for gas turbine combustion parts and furnaces due to its superior ductility and weldability.
Conclusion
Inconel X-750 proves to be a crucial nickel-chromium alloy valued for high strength, durability, and resistance to extreme temperatures. Its reliability suits aerospace, nuclear, and chemical applications. Whether you’re considering materials for high-stress components or exploring alloys for challenging environments, Nickel Alloy X-750 offers reliability and performance. For more details on how Alloy X-750 can benefit your projects, contact us today to discuss your specific needs and applications.
FAQs
What is the temperature range for INCONEL x750?
Inconel X750 is designed to perform across a wide temperature range, from cryogenic levels up to 1300°F (704°C) for sustained high strength and creep resistance. It maintains oxidation resistance up to 1800°F (982°C) for short-term applications, making it ideal for both extremely cold and high-temperature environments.
Is the Inconel X750 magnetic?
No, Inconel X-750 is a non-magnetic alloy. Its nickel-chromium composition makes it inherently non-magnetic, making it suitable for applications where magnetic interference is a concern.
How does Inconel X-750 perform at cryogenic temperatures?
Inconel X-750 performs exceptionally well at cryogenic temperatures, maintaining its toughness and stability. Its mechanical properties remain reliable even at low temperatures, making it suitable for applications in extreme cold environments, such as aerospace and cryogenic engineering.
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