Durable Inconel 718 Forgings: High Strength & Corrosion Resistance

Durable Inconel 718 Forgings: High Strength & Corrosion Resistance

"Alloy 718 (UNS N07718) forgings" generally refer to blanks or parts made from INCONEL 718 (GH4169) nickel-based superalloy through a forging process. It is a high-performance material that is widely used in high-temperature, high-strength, and highly corrosive environments.

What is 718 Alloy?

Firstly, it's essential to understand the 718 alloy itself. It is an austenitic, precipitation-hardening nickel-based superalloy primarily composed of nickel, with additions of chromium, iron, niobium, molybdenum, and other elements.

• Key Composition:

  • Nickel (Ni): The base element, providing excellent high-temperature stability and corrosion resistance.

  • Chromium (Cr): Provides outstanding oxidation and corrosion resistance.

  • Niobium (Nb) and Molybdenum (Mo): The primary strengthening elements, which form strengthening phases (such as the γ'' phase) through reactions with the matrix.

  • Iron (Fe): Present in significant amounts, which helps reduce cost while maintaining performance.

• Core Characteristics:

  • High Strength: Possesses extremely high strength from cryogenic temperatures up to approximately 700°C.

  • Excellent Fatigue and Creep Resistance: Resists deformation and fracture under long-term exposure to high temperatures and stress.

  • Good Oxidation and Corrosion Resistance: Capable of withstanding various harsh environments, such as acids and salt spray.

  • Excellent Fabricability: Compared to other high-performance superalloys, Alloy 718 offers relatively good forgeability and machinability.

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Application Areas

Due to their exceptional comprehensive properties, 718 forgings are widely used in cutting-edge industrial sectors:

1. Aerospace (Largest Application Sector):

   • Jet Engines: Turbine discs, compressor discs, blades, shafts, casings, combustion chamber components. These parts must operate under high temperatures, pressures, and rotational speeds, making 718 forgings the primary choice.

   • Rocket Engines: Turbopumps, valves, flanges.

   • Spacecraft Structural Components.

2. Energy Industry:

   • Gas Turbines: Similar to jet engines, used for hot-section components like blades and discs in power generation gas turbines.

   • Nuclear Power Equipment: Fasteners, springs, etc., in nuclear reactors.

3. Oil and Gas:

   • Used for wellhead equipment, valves, pipe connectors, flanges, etc., in deep-sea extraction, which require resistance to high pressure and highly corrosive environments.

4. Chemical and Process Industries:

   • Reactors, heat exchangers, pumps, valves that need to handle highly corrosive media.