Nickel-Based Alloy 718 in Gas Turbines

Nickel-based alloy 718 (referred to as Alloy 718, UNS N07718) is a precipitation-hardened superalloy with nickel as its main component. It possesses excellent mechanical strength, corrosion resistance, and high-temperature creep properties, making it widely used in high-temperature and high-pressure environments such as aero engines and industrial gas turbines. It maintains high strength at temperatures of 650-700°C, making it suitable for turbine components and significantly improving the efficiency and lifespan of gas turbines.
 

Applications in Gas Turbines

Alloy 718 is widely used in high-temperature components of gas turbines (especially aero and industrial gas turbines) due to its excellent strength and oxidation resistance below 700°C, enabling it to withstand centrifugal forces, thermal stresses, and corrosion. Typical applications include:

• Turbine Blades and Rotor Disks: Critical rotating components providing high fatigue and creep strength (e.g., GE F101/F110 engines).
• Casings and Rings: Supporting structures resistant to thermal fatigue, used for compressor and turbine casings.
• Transition Pieces and Combustion Chambers: Good thermal stability, resisting oxidation and hot corrosion.
• Fasteners and Instrumentation Components: Such as bolts and valves, suitable for high-pressure environments.