Inconel 718, a high-performance nickel-chromium alloy, stands out in advanced materials for its remarkable properties and wide-ranging applications. Known for its superior strength and resistance to extreme environments, Inconel 718 is a material of choice in industries that demand high reliability and performance. This blog explores the diverse uses of Inconel 718 and highlights its key products, including the Inconel 718 sheet and Inconel 718 bar.
What is Inconel 718?
Inconel 718 is a nickel-chromium alloy with iron, niobium, and molybdenum additions. It is renowned for its high strength, excellent oxidation resistance, and exceptional resistance to thermal and mechanical fatigue. The alloy is typically used in applications that involve high temperatures and corrosive environments.
Key Properties of Inconel 718
- High Strength: Inconel 718 maintains its strength at high temperatures, making it suited for applications requiring high load-bearing capacity.
- Corrosion Resistance: The alloy shows excellent resistance to oxidation, carburization, and other forms of chemical degradation.
- Thermal Stability: It performs well in cryogenic and high-temperature environments, making it versatile across various applications.
Applications of Inconel 718
- Aerospace Industry
Inconel 718 is extensively used in the aerospace sector due to its capacity to withstand harsh temperatures and high pressures. It is commonly found in turbine engines, rocket motors, and other critical components. The alloy’s ability to maintain its mechanical properties at high temperatures makes it ideal for engine parts and exhaust systems.
- Oil and Gas Industry
The oil and gas industry benefits from Inconel 718 resistance to corrosion and high temperatures. It is used to produce equipment such as drill collars, casing, and valves, which are subjected to harsh environments. The alloy’s durability ensures reliability and safety in oil and gas operations.
- Nuclear Power
Inconel 718 resistance to radiation-induced degradation makes it a suitable material for nuclear reactors. It is used in components like reactor cores and fuel assemblies where high strength and resistance to radiation are crucial.
- Marine Applications
The alloy’s resistance to seawater corrosion makes it an excellent choice for marine applications. It is used in components like pumps, valves, and shafts exposed to harsh marine environments.
- Chemical Processing
Inconel 718 is used in chemical processing due to its opposition to caustic chemicals and high temperatures. It is used in reactors, pumps, and heat exchangers that handle aggressive chemicals.
Products: Inconel 718 Sheet and Inconel 718 Bar
- Inconel 718 Sheet: The Inconel 718 sheet is used in applications where thin, flat material is required. Its excellent strength and resistance properties make it suitable for manufacturing components that need to endure harsh environments while maintaining dimensional stability.
- Inconel 718 Bar: The Inconel 718 bar is often used in applications requiring structural stability and durability. It is commonly utilized in the aerospace and automotive industries, where its high strength and thermal stability are essential for critical components.
Inconel 718, Customizable Mechanical Properties
Additionally, like other nickel-iron-based superalloys, Inconel 718 can be hardened. This property makes it especially suitable for structural components that operate at high temperatures.
Inconel 718 is strengthened by combining two key mechanisms: solid solution hardening and precipitation hardening. In solid solution hardening, elements such as iron, chromium, molybdenum, and niobium substitute for nickel within the metallic matrix. In precipitation hardening, ordered intermetallic phases, γ’ and γ”, form to enhance strength.
Titanium and aluminium contribute to the formation of the γ’ phase (Ni3(Ti, Al)), which is metastable and further hardened by the solid solution of niobium and titanium at room temperature and tungsten or molybdenum at elevated temperatures.
At around 650°C, niobium precipitates as the γ” phase (Ni3Nb), which provides exceptional mechanical properties at both very low and moderately high temperatures. Although both γ’ and γ” phases are present in the aged condition, γ” is the predominant strengthening agent. γ” precipitates are disk-shaped, measuring 5-9 nm in thickness and approximately 60 nm in diameter.
In addition to γ’ and γ”, structural components include primary carbides formed by elements such as chromium and titanium and secondary carbides created by chromium, cobalt, molybdenum, and tungsten. However, undesirable phases may also form in the alloy
Conclusion
Inconel 718 is a versatile and high-performance alloy with various applications across various industries. Its superior strength, erosion resistance, and thermal stability make it an invaluable material in demanding environments. Whether in the form of an Inconel 718 sheet or Inconel 718 bar, this alloy plays a critical role in advanced engineering and technology.
For more information on Inconel 718 products, including sheets and bars, consult with industry experts to ensure you select the best material for your specific application.
