UNS N07718|2.4668|Inconel 718 Seamless Pipe
Distinguished by its precipitation-hardening capabilities, our Inconel 718 tubing offers superior resistance to creep-rupture and high tensile strength at temperatures ranging from cryogenic levels up to 704°C (1300°F). This makes them indispensable for mission-critical applications in aerospace engines, high-strength fasteners, and downhole oil & gas tools. Through advanced cold-drawing and precise vacuum heat treatment, XinZhe ensures every pipe maintains optimal microstructure and excellent weldability without post-weld cracking, even in aggressive corrosive media.
"Our Inconel 718 pipes offer exceptional resistance to chloride and sulfide stress corrosion cracking, meeting NACE MR0175 standards."
What Is Seamless Inconel 718 Pipe?
Seamless Inconel 718 pipe (UNS N07718) is a high-performance, precipitation-hardenable nickel-based superalloy pipe manufactured from a solid billet through a seamless process. Unlike welded pipes, it contains no weld seams, ensuring superior structural integrity, pressure resistance and reliability in critical applications.
Designed for extreme environments, Inconel 718 maintains excellent mechanical properties from cryogenic conditions up to 704°C, while offering outstanding resistance to oxidation and corrosion. The alloy is strengthened by controlled additions of Niobium (Nb) and Molybdenum (Mo), enabling age-hardening heat treatment.
This makes it a preferred material in aerospace, subsea oil & gas and nuclearindustries.
Key Features and Technical Advantages
High Strength and Creep Resistance
precipitation hardening provides exceptional tensile and yield strength, enabling thinner wall thickness and reduced system weight.
Excellent Corrosion Resistance
superior resistance to chloride-induced SCC, pitting and crevice corrosion, especially in sour service (H₂S) and marine environments.
Outstanding Thermal Stability
retains mechanical properties from cryogenic temperatures up to 704°C, ideal for gas turbines and aerospace systems.
Precision Manufacturing (ASTM B829)
tight dimensional tolerances ensure excellent concentricity and wall thickness control for critical fluid systems.
Good Weldability
compared with other precipitation-hardening alloys, Inconel 718 exhibits strong resistance to post-weld cracking.
Product Specifications and Data
Chemical Composition
The composition of Inconel 718 is carefully balanced to achieve its superior strength and corrosion resistance.
| Grade | Ni | Cr | Fe | Nb | Mo | Ti | Mn | Si | Co | C | P | S | B |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N07718 | 50.0–55.0 | 17.00–21.00 | Balance | 4.75–5.50 | 2.80–3.30 | 0.65–1.15 | ≤ 0.35 | ≤ 0.35 | ≤ 1.0 | ≤ 0.08 | ≤ 0.015 | ≤ 0.015 | ≤ 0.006 |
Typical Mechanical Properties
Inconel 718 is specifically designed to maintain its strength and shape in high-stress, corrosive environments (aged condition).
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| ≥ 1240 MPa | ≥ 1034 MPa | ≥20% | ≤40 HRC |
Typical Physical Properties
| Density | Melting Point | Thermal Expansion | Thermal Conductivity | Modulus of Elasticity | Electrical Resistivity |
|---|---|---|---|---|---|
| 8.22 g/cm³ | 1260–1336 °C | 13.0 µm/m·°C (20-100°C) | 11.4 W/m·K (20°C) | 200 GPa | 1.2 × 10⁻⁶ Ω·m (20°C) |
Size Tolerance Chart
Seamless pipe dimensional tolerances per ASTM B829(mm):
| Nominal Outside Diameter | OD Tolerance (Plus/Minus) | Wall Thickness — % of Nominal Wall | Wall Thickness — % of Minimum Wall |
|---|---|---|---|
| Over 0.400 (10) to 5/8 (16), excl. | ±0.005 in. (0.13 mm) | +15%/−15% | +30%/−0 |
| 5/8 (16) to 1 1/2 (38), incl. | ±0.0075 in. (0.19 mm) | +10%/−10% | +22%/−0 |
| Over 1 1/2 (38) to 3 (76), incl. | ±0.010 in. (0.25 mm) | +10%/−10% | +22%/−0 |
| Over 3 (76) to 4 1/2 (114), incl. | ±0.015 in. (0.38 mm) | +10%/−10% | +22%/−0 |
| Over 4 1/2 (114) to 6 (152), incl. | ±0.020 in. (0.51 mm) | +12.5%/−12.5% | +28%/−0 |
| Over 6 (152) to 6 5/8 (168), incl. | ±0.025 in. (0.64 mm) | +12.5%/−12.5% | +28%/−0 |
| Over 6 5/8 (168) to 8 5/8 (219), incl. | ±0.031 in. (0.79 mm) | +12.5%/−12.5% | +28%/−0 |
Industrial Applications of Seamless Inconel 718 Pipes
Aerospace and Defense
- Jet engine components
- Fuel lines
- Rocket engine systems
Oil and Gas (Upstream and Subsea)
- Downhole tools
- Wellhead equipment
- Subsea control systems
- Sour gas service
Nuclear Power
- Reactor components
- High-strength fasteners
- Pressure systems
Chemical Processing
- Heat exchangers
- Reactors
- Piping systems handling aggressive media
Quality Assurance and Certification
Material Certification
EN 10204 3.1 / 3.2 Mill Test Certificate with full traceability from raw material to finished product.
Non-Destructive Testing
PMI, Ultrasonic Testing (UT), Eddy Current Testing (ET) and Hydrostatic Testing (HT).
Mechanical and Corrosion Testing
impact test, flattening/flaring test and intergranular corrosion (IGC) testing.
Dimensional and Surface Inspection
surface roughness control and precision OD/WT measurement; third-party inspection (ABS, DNV, BV, TÜV, Lloyd’s Register) available.
Frequently Asked Questions About Inconel 718 Pipe
What makes Inconel 718 different from other nickel alloys?
It is precipitation-hardenable: niobium and molybdenum additions enable age-hardening heat treatment, delivering very high strength (≥1240 MPa tensile) that solid-solution alloys do not reach.
What temperature range does Inconel 718 cover?
Mechanical properties are retained from cryogenic conditions up to 704°C, making it suitable for gas turbines, rocket systems and cryogenic service alike.
Is Inconel 718 suitable for sour gas service?
Yes. It offers superior resistance to chloride SCC, pitting and crevice corrosion, especially in sour service (H₂S) and marine environments.
What standards apply to seamless Inconel 718 pipe?
Dimensional requirements follow ASTM B829; confirm the applicable product standard and condition (aged or solution treated) on the purchase order.
Why is Inconel 718 considered weldable?
Compared with other precipitation-hardening alloys, it exhibits strong resistance to post-weld cracking.
Ready to Request a Quotation?
Send your Inconel 718 pipe enquiry with grade, UNS N07718, size and schedule, length, quantity, material condition, delivery destination and inspection documents — you will get a written quotation stating the specification and edition, delivery condition, documents included and lead time.
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