INCONEL 718
Inconel 718
Inconel 718, with a density of 8.19 g/cm³, is a versatile nickel alloy known for high strength and corrosion resistance, ideal for various applications.
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Material Specification
| Property | Specification |
|---|---|
| Material Name | Inconel 718 |
| Standard | ASTM B637, AMS 5662, AMS 5663, DIN 2.4668 |
| Chemical Composition | Ni 50-55%, Cr 17-21%, Fe balance, Nb+Ta 4.75-5.5%, Mo 2.8-3.3%, Ti 0.65-1.15%, Al 0.2-0.8%, Co ≤1.0%, Mn ≤0.35%, Si ≤0.35%, C ≤0.08% |
| Density | 8.19 g/cm³ |
| Melting Point | 1260-1340°C (2300-2440°F) |
| Tensile Strength | ≥965 MPa (Annealed) |
| Yield Strength (0.2%) | ≥550 MPa (Annealed) |
| Elongation | ≥30% (Annealed) |
| Hardness | ≤363 HB (Annealed) |
| Corrosion Resistance | Excellent resistance to oxidation and corrosion at high temperatures |
| Applications | Aerospace, Gas Turbines, Nuclear Reactors, Marine, Oil & Gas |
Possible Alternative Grades
| Alternative Grade | Key Features | Applications |
|---|---|---|
| Waspaloy | High-temperature strength, oxidation resistance | Aerospace, gas turbines |
| Incoloy 925 | Corrosion resistance, high strength | Oil & gas, marine, chemical processing |
| Alloy X-750 | Creep resistance, good mechanical properties | Aerospace, nuclear reactors |
| Alloy 625 | Superior corrosion resistance, high strength | Chemical processing, marine, aerospace |
| Alloy 706 | High strength, easy fabrication | Aerospace, industrial gas turbines |
| Haynes 230 | Exceptional high-temperature strength | Thermal environments, gas turbines |
| Rene 41 | Excellent high-temperature strength and oxidation | Aerospace, turbine engines |
| Hastelloy C-276 | Exceptional corrosion resistance | Chemical processing, pollution control |
Inventory
| Item | Specifications |
|---|---|
| 718 Sheets | Thickness: 3mm, Width: 1500mm, Length: 3000mm |
| 718 Plates | Thickness: 10mm, Width: 2000mm, Length: 6000mm |
| 718 Rods | Diameter: 50mm, Length: 3000mm |
| 718 Tubes | OD: 100mm, Wall Thickness: 5mm, Length: 6000mm |
| 718 Wires | Diameter: 1.2mm |
| 718 Forgings | Custom shapes as per specifications |
| 718 Fasteners | Bolts, nuts, washers (M12-M24) |
Technical Data Sheet
| Element | Min (%) | Max (%) |
|---|---|---|
| Carbon (C) | – | 0.08 |
| Manganese (Mn) | – | 0.35 |
| Silicon (Si) | – | 0.35 |
| Phosphorus (P) | – | 0.015 |
| Sulfur (S) | – | 0.015 |
| Chromium (Cr) | 17.00 | 21.00 |
| Nickel (Ni) | 50.00 | 55.00 |
| Molybdenum (Mo) | 2.80 | 3.30 |
| Niobium/Columbium (Nb/Cb) | 4.75 | 5.50 |
| Titanium (Ti) | 0.65 | 1.15 |
| Aluminum (Al) | 0.20 | 0.80 |
| Cobalt (Co) | – | 1.00 |
| Tantalum (Ta) | – | 0.05 |
| Boron (B) | – | 0.006 |
| Copper (Cu) | – | 0.30 |
| Lead (Pb) | – | 0.0005 |
| Bismuth (Bi) | – | 0.00003 |
| Selenium (Se) | – | 0.0003 |
| Iron (Fe) | Balance |
| Property | Value | Condition |
|---|---|---|
Tensile Strength | 690 MPa (100 ksi) | @ Room Temperature |
Yield Strength | 483 MPa (70 ksi) | @ Room Temperature |
Elongation | 40% | @ Room Temperature |
Reduction of Area | 50% | @ Room Temperature |
Hardness (Brinell) | ≤ 217 | @ Room Temperature |
Modulus of Elasticity | 207 GPa (30,000 ksi) | @ Room Temperature |
Poisson’s Ratio | 0.29 | @ Room Temperature |
Thermal Conductivity | 9.6 W/m·K | @ 25°C |
| Property | Value |
|---|---|
| Density | 8.44 g/cm³ |
| Melting Point | 1290°C – 1350°C (2350°F – 2460°F) |
| Specific Heat | 0.46 J/g·K |
| Thermal Expansion (α) | 13.0 µm/m·K @ 20°C – 100°C |
| Electrical Resistivity | 1.45 µΩ·m |
Corrosion Resistance
Excellent Corrosion Resistance: Inconel 718 provides outstanding resistance to corrosion in various environments, both inorganic and organic.
Wide Range of pH Tolerance: The alloy is effective in resisting corrosion across a broad range of acidity and alkalinity.
Nickel Contribution: Nickel enhances resistance to corrosion, especially in environments containing strong oxidizing agents.
Stress Corrosion Cracking: The alloy is particularly effective against chloride-ion stress corrosion cracking.
Chromium Benefits: Chromium improves the alloy’s ability to resist attacks from oxidizing agents and sulfur compounds.
Molybdenum Support: Molybdenum contributes significantly to pitting resistance in various corrosive media.
Thermal Properties
Physical Constants and Thermal Data
- Thermal Conductivity: Maintains efficient heat transfer performance, suitable for high-temperature environments.
- Specific Heat Capacity: Supports excellent thermal energy absorption, ensuring stability under fluctuating temperatures.
- Thermal Expansion: Demonstrates low thermal expansion, minimizing deformation under heat stress.
Typical Applications
- Aerospace components (turbine blades, engine parts)
- High-temperature industrial equipment
- Oil and gas sector tools and machinery
Fabrication and Welding Information
- Welding Process: Readily welded using the gas tungsten-arc (TIG) process with INCONEL Filler Metal 718.
- Post-Weld Treatment: Highest ductility and tensile properties are achieved by annealing at 1950°F before aging.
- Age Hardening: The alloy’s slow response to age hardening allows for direct age-hardening after welding without requiring intermediate stress relief.
Performance
- Joint efficiencies close to 100% have been achieved in tests, particularly for annealed plates that were welded and aged.
- Superior properties are obtained when parts are re-annealed after welding but prior to aging.
Brazing Considerations
- Silver Brazing: Avoid silver brazing compounds as they can induce stress cracking, particularly in cold-worked or precipitation-hardened alloys.
- Cadmium-Free Alloys: Cadmium-containing brazing materials should also be avoided to prevent aggravating crack formation.
Heat Treatment
Solution Annealing
- Purpose: Dissolves precipitates, homogenizes the microstructure, and prepares the alloy for subsequent aging treatments.
- Temperature: Typically 980–1020°C (1800–1870°F).
- Process:
- Heat the material to the solution annealing temperature.
- Hold for a specified time depending on the thickness.
- Rapidly cool, usually by air cooling or water quenching.
Aging Heat Treatment
- Purpose: Enhances strength and hardness by promoting the precipitation of γ′ (gamma prime) and γ″ (gamma double prime) phases.
- Standard Aging Cycle:
- Heat to 720°C (1330°F) and hold for 8 hours.
- Cool at a controlled rate of 50°C/hour to 620°C (1150°F).
- Hold at 620°C for an additional 8 hours.
- Air cool to room temperature.
Double Aging
- Purpose: Achieves the highest combination of tensile and creep strength.
- Process: Similar to standard aging but includes additional steps to refine the precipitation process for specific applications.
Stress Relief
- Purpose: Reduces residual stresses caused by machining or forming.
- Temperature: Typically 870–900°C (1600–1650°F).
- Process: Heat the material to the desired stress-relief temperature, hold, and cool slowly.
Applications
Customized Package
Oil-Coated Paper
Thick Woven Plastic Bag
Air Cushion Film + Wooden Case
At Alloyxpert
- Sheets and plates are wrapped in oil-coated paper for corrosion protection, placed on wooden pallets, and strapped securely to prevent shifting during transport.
- Bars and rods are bundled together using thick woven plastic bags and carefully packed, ensuring each bundle weighs no more than 1500 KG for safe handling.
- Tubes and pipes are packed in air cushion film to protect them from dirt and scratches. For added protection, they are placed in wooden cases to prevent damage during transit.
Logistics
By Sea
By Air
By Land
Alloyxpert provides three transportation options: sea, land, and air. Sea transportation is the most commonly chosen method for most orders and is therefore regarded as the default transportation mode. Quotations are typically based on terms such as FOB, CFR, or CIF. For urgent requirements, we also offer air transportation, while land transportation is available for specific regional needs.
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