Inconel Alloy 718 Welding Wire N07718 GH4169 NiCr19Nb5Mo3 2.4668 Superior Corrosion Resistance for Critical Aerospace Applications

Inconel 718 Welding Wire (UNS N07718) is a high-strength, corrosion-resistant superalloy, widely used in applications that demand superior mechanical properties at elevated temperatures. This nickel-chromium alloy contains notable amounts of molybdenum, niobium, and titanium, which enhance its suitability for welding and joining materials in high-temperature, high-stress environments.

Primarily used in industries such as aerospace, power generation, and chemical processing, Inconel 718 Welding Wire (UNS N07718) is renowned for its excellent weldability, exceptional strength at elevated temperatures, and outstanding corrosion resistance. These qualities make it the alloy of choice for components exposed to harsh, high-temperature conditions. Post-welding, the alloy undergoes heat treatment to restore its strength and toughness, ensuring reliable, long-term performance in demanding applications.

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Key Features of Inconel 718 Welding Wire:

• Composition (Approximate):

Nickel: 50-55%

Chromium: 17-21%

Molybdenum: 2.8-3.3%

Niobium: 4.75-5.5%

Titanium: 0.65-1.15%

Iron: Balance, with small amounts of aluminum, cobalt, and other elements.

• Mechanical Properties:

Tensile Strength: Typically around 1,200-1,400 MPa (175-200 ksi) at room temperature. The strength increases significantly at elevated temperatures (up to 700°C or 1300°F).

Yield Strength: Around 1,000-1,100 MPa (145-160 ksi) at room temperature.

Elongation: Approximately 20-30% in the as-welded condition.

Hardness: Hardness is generally around 35-45 HRC after heat treatment.

• Welding Characteristics:

Weldability: Inconel 718 welding wire exhibits excellent weldability in all common welding processes, including TIG, MIG, and stick welding (SMAW). It can also be used for gas tungsten arc welding (GTAW) and plasma arc welding (PAW).

Heat-Affected Zone (HAZ): Inconel 718 welding wire is designed to minimize the effects of the heat-affected zone, ensuring that the properties of the welded material remain robust after welding, especially at high temperatures.

Post-Weld Heat Treatment: After welding, Inconel 718 requires aging heat treatment to optimize its mechanical properties and to restore the strength of the weld and base metal. The typical aging treatment involves heating to about 720-740°C (1330-1365°F) followed by air cooling.

• Corrosion and Oxidation Resistance:

Corrosion Resistance: Inconel 718 exhibits excellent resistance to a variety of corrosive environments, including oxidation, pitting, and crevice corrosion. It is particularly resistant to high-temperature oxidation and general corrosion in reducing environments.

Oxidation Resistance: The alloy can withstand exposure to temperatures of up to 700°C (1300°F) while maintaining resistance to oxidation, making it ideal for use in high-temperature, corrosive environments.

• Thermal Properties:

Melting Point: Around 1280-1330°C (2340-2425°F).

Thermal Conductivity: Relatively low, which is typical for superalloys, helping to prevent heat degradation in critical applications.

Coefficient of Thermal Expansion: Similar to other nickel-based alloys, Inconel 718 exhibits moderate expansion at elevated temperatures.

Applications:

• Aerospace: Components in jet engines, gas turbines, and other high-temperature, high-stress aerospace parts, including turbine blades, disks, and seals.
• Marine: Used in marine turbine engines and other components exposed to high temperatures and seawater environments.
• Power Generation: Gas turbines, steam turbines, and combustion chambers in power plants.
• Chemical Processing: Equipment exposed to aggressive environments, such as reactors, heat exchangers, and piping systems.
• Oil & Gas: Equipment for high-pressure, high-temperature applications, especially in the upstream sector.