Inconel 718 UNS N07718: Properties, Applications & Machining Guide for Industries

Inconel 718 was developed in the early 1960s to meet the demand for a high-strength, weldable superalloy for jet engine components. Its unique composition, particularly the addition of niobium and molybdenum, allows for precipitation hardening, which creates exceptionally high strength without compromising weldability. This breakthrough set it apart from other nickel-based superalloys of its time. 

The alloy's strength is derived from the precipitation of fine gamma double-prime (γ'') particles within the metal matrix during heat treatment. This microstructure is stable and provides excellent mechanical properties at both elevated and cryogenic temperatures. As a result, Inconel 718 quickly became a cornerstone material in aerospace engineering and has since expanded into other high-technology sectors. For a broader perspective on nickel alloys, explore our Inconel alloys overview. 

Key characteristics derived from its composition include: 

• An austenitic crystal structure that remains stable across a wide temperature range. 
• Non-magnetic properties, which are critical for certain instrumentation and electronic applications. 
• A protective passive oxide layer that forms on the surface, delivering superior corrosion resistance. 
• The specific balance of elements in its chemical makeup is crucial for achieving its performance characteristics. 

The performance of Inconel 718 in extreme service conditions is defined by its mechanical, corrosion, and thermal properties. Engineers select this alloy when reliability is paramount and components must withstand intense stress, high temperatures, and corrosive media simultaneously. As leading Inconel 718 suppliers in the UAE, we ensure our materials meet these exacting property standards. 

The most notable Inconel 718 properties include: 

• High Mechanical Strength: In its age-hardened condition, UNS N07718 exhibits an ultimate tensile strength (UTS) often exceeding 1275 MPa (185 ksi) at room temperature. It maintains excellent strength up to approximately 700°C. 
• Superb Creep-Rupture Strength: It resists deformation under constant load at high temperatures, a critical requirement for gas turbine and jet engine components. 
• Excellent Corrosion Resistance: The high chromium and nickel content provides resistance to a wide range of corrosive environments, including pitting and crevice corrosion in chloride-heavy settings common in marine and chemical processing industries. It performs reliably up to 980°C. 
• Outstanding Cryogenic Performance: Unlike many steels that become brittle at low temperatures, Inconel 718 retains its strength and ductility down to cryogenic levels, making it suitable for liquefied natural gas (LNG) and space applications. 

The exceptional properties of Inconel 718 make it indispensable across several high-stakes industries in the UAE and worldwide. Its ability to function reliably under extreme conditions ensures safety, efficiency, and longevity for critical systems. The versatility of Inconel 718 applications spans from deep-sea drilling to outer space. 

Key industrial uses include: 

• Aerospace: This sector accounts for over 50% of Inconel 718 usage. It is integral to gas turbine engines for components like compressor discs, blades, seals, and shafts. It is also used in liquid-fueled rocket engines, fasteners, and instrumentation parts. Learn more about its role in Inconel 718 for aerospace.
• Oil & Gas: Inconel 718 is vital for downhole equipment exposed to high pressures, high temperatures (HPHT), and corrosive elements like hydrogen sulfide (H2S) and carbon dioxide (CO2). Applications include wellhead components, valves, packers, and shafts for subsurface safety valves. Nifty Alloys supplies certified Inconel 718 round bar for these demanding jobs. 
• Marine Engineering: Its excellent resistance to chloride-ion stress-corrosion cracking makes it suitable for marine propulsion shafts, submarine components, and high-strength fasteners in saltwater environments. 
• Nuclear Power: Used in control rod parts, fuel element grids, and core structural components where high strength and resistance to aqueous corrosion are essential for safety and long service life. 
• Additive Manufacturing (3D Printing): The good weldability of Inconel 718 has made it a popular choice for Inconel 718 3D printing via processes like Direct Metal Laser Sintering (DMLS). This enables the creation of complex, lightweight parts for aerospace and tooling applications. 

Selecting the right material requires comparing its performance against other available options. While Inconel 718 is a premier high-strength superalloy, its specific advantages become clearer when contrasted with other common engineering materials like Inconel 625 and 316L stainless steel. The choice often depends on balancing strength, temperature resistance, corrosion performance, and cost. A detailed analysis can be found in our guide on stainless steel & superalloys. 

The following table compares key characteristics to help guide material selection for your specific application. This comparison, particularly Inconel 718 vs Inconel 625, is a frequent topic among engineers. 

Fabricating components from Inconel 718 presents unique challenges due to its high strength and rapid work-hardening tendency. Proper techniques for machining Inconel 718, welding, and heat treatment are critical to achieving desired component performance and avoiding premature tool wear or material failure. Nifty Alloys offers materials optimized for fabrication and can provide guidance through our superalloy machining services. 

Machining Tips 

The key to machining UNS N07718 is managing its work-hardening nature. 

• Tooling: Use sharp, positive rake angle carbide tools. Ceramic tools can be used for finishing at higher speeds. 
• Speeds and Feeds: Employ low cutting speeds (typically 15-30 m/min) and high, constant feed rates to stay ahead of the work-hardened zone. 
• Machine Rigidity: Use a powerful, rigid machine setup to minimize vibration and chatter, which can accelerate work hardening. 
• Coolant: A high-pressure, high-volume coolant is essential to dissipate heat and clear chips effectively. 
• Depth of Cut: Take a sufficient depth of cut to get below the previously work-hardened layer from the last pass. 

Inconel 718 heat treatment is fundamental to developing its signature properties. Welding must be carefully controlled to prevent cracking issues. 

• Welding: Weld the material in the annealed condition. Gas Tungsten Arc Welding (GTAW/TIG) and Plasma Arc Welding (PAW) are preferred methods. Use matching filler metals (e.g., AWS A5.14 ERNiFeCr-2). Keep heat input low and use stringer beads. 
• Post-Weld Stress Relief: A stress relief treatment may be necessary before aging, especially on complex or heavily restrained weldments. 
• Solution Annealing: Heat the fabricated part to a temperature between 925°C and 1010°C and hold, followed by rapid cooling. This dissolves brittle phases and prepares the material for aging. 
• Precipitation Hardening (Aging): This is typically a two-step process: heat to 720°C for 8 hours, furnace cool to 620°C, hold for another 8 hours, then air cool. This cycle precipitates the strengthening phases and develops the final high-strength properties. 

As a leading stockist, Nifty Alloys provides Inconel 718 in forms and specifications that meet the stringent requirements of the UAE's industrial base. All our materials are fully certified and traceable, ensuring they comply with international standards for critical applications. When you need to buy Inconel 718 in Dubai, we are your reliable source. 

We supply Inconel 718 in a variety of forms, including: 

• Round Bar: The most common form, used for machining shafts, fasteners, and valves. 
• Plate & Sheet: Used for fabricating structural components, casings, and ducting. 
• Forgings: Custom-shaped components for high-stress applications like turbine discs and connecting rods. 
• Pipe & Tube: For fluid transport in corrosive, high-pressure environments. 

Our stock conforms to major international specifications, such as: 

• AMS 5662 / AMS 5663: Aerospace specifications for bar, forgings, and rings. 
• ASTM B637: Standard specification for precipitation-hardening nickel alloy bars, forgings, and forging stock for high-temperature service. 
• NACE MR0175/ISO 15156: For materials used in H2S-containing environments in oil and gas production. 

To inquire about current stock levels and buy Inconel 718 round bar in Dubai, check our product page or contact our sales team for an immediate quote. 

Understanding the cost structure and sourcing logistics for Inconel 718 is crucial for project budgeting and supply chain management. As a specialty superalloy, its price is significantly higher than that of stainless steels due to its complex composition and processing requirements. The Inconel 718 round bar price in the UAE can fluctuate based on several market factors. 

Price Factors 

Sourcing & Storage Tips 

When sourcing Inconel 718, partner with a reputable stockist like Nifty Alloys. We are one of the most reliable Inconel 718 suppliers in the UAE, providing certified materials with full traceability. For secure storage, keep the alloy in a dry, clean environment and separate it from carbon steel to prevent contamination. 

For a formal quotation or to discuss your project requirements, contact our team at sales@niftyalloys.com. 

• ISO-Certified Supplier: Our quality management system is certified, guaranteeing that you receive materials that meet the highest standards. 
• Extensive Dubai Stock: We maintain a comprehensive inventory of Inconel 718 in Dubai, ensuring fast delivery across the UAE and the wider region. 
• Full Traceability and MTCs: Every piece of material we supply comes with a Mill Test Certificate (MTC) for complete quality assurance and traceability. 

To provide immediate answers to common questions from engineers and procurement specialists, this section addresses the most frequent inquiries about Inconel 718. 

What is Inconel 718 used for? 

• Inconel 718 is primarily used for high-stress, high-temperature applications. Common uses include gas turbine engine components like discs and blades, rocket motors, nuclear reactors, downhole shafts in the oil and gas industry, and high-strength bolting. 

Is Inconel 718 magnetic? 

• No, Inconel 718 is non-magnetic. Its austenitic crystal structure, which is maintained from cryogenic temperatures up to its melting point, makes it non-magnetic even after severe cold working. 

Does Inconel 718 rust? 

• No, Inconel 718 does not rust in the conventional sense. It exhibits outstanding corrosion resistance in a wide range of environments, including resistance to pitting, crevice corrosion, and stress-corrosion cracking, particularly in chloride- and sulfide-containing settings. 

How hard is Inconel 718 to machine? 

• Machining Inconel 718 is very challenging. It has a high tendency to work-harden rapidly, which requires rigid machine setups, low cutting speeds, high-pressure coolants, and sharp, durable tooling, typically made from carbide. 

What is the difference between Inconel 718 and 625? 

• The main difference is that Inconel 718 is precipitation-hardenable and offers significantly higher tensile and creep-rupture strength up to 700°C. Inconel 625 is solid-solution strengthened and provides superior corrosion and oxidation resistance, especially at higher temperatures. You can learn more in our detailed comparison of Inconel 625 (UNS N06625). 

What is the heat treatment for Inconel 718? 

• The standard heat treatment for Inconel 718 involves a solution anneal followed by a two-step precipitation aging process. A typical cycle is solution annealing at 925-1010°C, followed by aging at 720°C for 8 hours, furnace cooling, and a final age at 620°C for another 8 hours to develop its high-strength properties. 

Is Inconel 718 weldable? 

• Yes, Inconel 718 is readily weldable, especially in the annealed condition. Common methods include Gas Tungsten Arc Welding (GTAW) and Plasma Arc Welding (PAW). Post-weld heat treatment is necessary to maintain strength and prevent age-cracking. 

What is the density of Inconel 718? 

• The density of Inconel 718 is 8.19 g/cm³ (0.296 lb/in³). This is an important property for calculating weight in aerospace and other critical applications. 

What factors affect the cost of Inconel 718? 

• The primary cost driver for Inconel 718 is the market price of its main alloying elements, particularly nickel and niobium. Other factors include the form (bar, plate, etc.), specific certifications required, order volume, and machining or processing complexity. 

Where can I buy Inconel 718 in the UAE? 

• You can buy certified Inconel 718 stock in various forms from specialized suppliers in the UAE. Nifty Alloys is a leading Dubai-based stockist offering Inconel 718 with full traceability and Mill Test Certificates to meet the demands of local industries. 

Conclusion 

Inconel 718 (UNS N07718) stands as a premier material for industries where performance under pressure is non-negotiable. Its unmatched combination of high strength, temperature stability, and corrosion resistance secures its place in the most critical applications, from aerospace propulsion to deep-sea energy exploration. The ongoing development in Inconel 718 3D printing further expands its potential, enabling the rapid production of complex, optimized parts for next-generation technologies. 

For engineering professionals and procurement managers in the UAE, a reliable supply of certified Inconel 718 is essential for project success. Partnering with a knowledgeablesupplier ensures that your materials meet the exact specifications required for safety and performance. At Nifty Alloys, we are committed to being that partner.