Inconel 718

What Is Inconel 718?

Inconel 718 is a high-strength, corrosion-resistant nickel-chromium alloy with traces of niobium, titanium and aluminum. Its increased toughness and strength are sustainable in cryogenic and elevated temperatures. The unique Inconel 718 composition allows for corrosion resistance in various environments, including seawater, hydrogen sulfide, CO2, elemental sulfur and chloride ions at vast temperatures.

It can be fabricated in the annealed or age-hardened condition. The annealed condition gives a slightly longer tool life, while the age-hardened condition gives a better finish and better chip action on chip breaker tools. Alloy 718 also features excellent welding properties compared to other Inconel alloys.

Inconel 718 Benefits

Inconel 718 provides several advantages, making it a preferred choice in various applications:

• Wide temperature range: Maintains good strength and ductility from freezing temperatures up to 704 °C/1,300 °F.
• Corrosion resistance: Exhibits excellent resistance to corrosion in seawater and industrial acids.
• Spark-resistant: This alloy is both non-magnetic and spark-resistant, enhancing safety in specific environments.
• Cracking resistance: Offers remarkable resistance to chloride stress corrosion and sulfide stress cracking.
• High fatigue strength: Demonstrates high fatigue strength, particularly in seawater applications.

Applications of Inconel 718

Inconel fasteners play a critical role in various industries, including:

• Aerospace components: Inconel 718 is used in jet engines of commercial airliners such as the Boeing 787. These fasteners must withstand some of the harshest operating conditions, including extreme heat and pressure, for safety and optimal performance.
• Nuclear reactors and power plants: Inconel 718 is used in nuclear reactors, containment vessels and valves because it resists high temperatures and radiation.
• Oil and gas: Inconel fasteners provide durability in the harsh conditions of oil extraction and processing. Inconel 718 is ideal for turbines, wellhead components, choke stems, fasteners, gate valves, clamps, tubing hangers, packers and downhole equipment.

Types of Inconel 718 Fasteners Available

Inconel fasteners come in various forms to suit different applications:

• Bolts and screws
• Nuts
• Studs and rods
• Washers
• U bolts
• Vented products
• Socket products

How to Choose the Right Inconel Fastener for Your Application

Inconel fasteners are highly valued for their resistance to oxidation and corrosion, strength at high temperatures, and thermal stability, making them suitable for various applications. They are also less likely to experience galvanic corrosion than other alloys. Choosing the right Inconel grade depends on these factors:

• Temperature: Inconel fasteners are ideal for high-temperature applications in power plants, aerospace and industrial settings.
• Chemical environment: Select fasteners that can withstand the specific corrosive elements present to prevent contamination or failure during operation. For instance, Inconel 718 is highly resistant to environments with high levels of chlorides, sodium thiosulfates or calcium phosphates.
• Load-bearing capacity and joint type: Ensure the fasteners can handle the maximum load without failing and choose the right type for specific joints and locations, such as bolts, nuts or screws.
• Application: Fasteners with superior strength and corrosion resistance are necessary for highly critical applications, such as aerospace or power plants.

Most importantly, select the right supplier with a strong reputation and quality control. Ensure they provide essential documentation, like material test reports and compliance certificates, for traceability and assurance. Consult with the experts at Nickel Systems to help you find the right nickel alloy for your needs.