Inconel 718 (UNS N07718) – Supplier of Round Bars, Seamless Tubes & Plates | Shanghai Hangbo Alloy Group
Date: 2026年7月10日 Categories: News Views: 326
By Shanghai Hangbo Alloy Group Co., Ltd. | ISO 9001:2015 Certified | Est. 2012 | Shanghai, China
Quick Answer: What Is Inconel 718?
Inconel 718 (UNS N07718 / W.Nr. 2.4668) is a high-strength, precipitation-hardenable nickel-chromium superalloy characterized by its exceptional tensile, fatigue, creep, and rupture strength at temperatures up to 704°C (1300°F). Strengthened by additions of niobium, molybdenum, aluminum, and titanium, it offers superior weldability and resistance to post-weld cracking compared to other age-hardenable superalloys. Shanghai Hangbo Alloy Group supplies Inconel 718 as precision round bars, seamless tubes, and plates, providing the backbone for modern aero-engines and high-pressure oilfield equipment.
Key Properties at a Glance
| Property | Value |
|---|---|
| UNS Number | N07718 |
| Density | 8.19 g/cm³ (0.296 lb/in³) |
| Melting Range | 1260 – 1336 °C (2300 – 2435 °F) |
| Max Service Temp. | 704 °C (1300 °F) for strength |
| Tensile Strength (Aged) | ≥ 1240 MPa (180 ksi) |
| Yield Strength (Aged) | ≥ 1030 MPa (150 ksi) |
| Elongation (Aged) | ≥ 12% |
| Thermal Conductivity | 11.4 W/m·K (at 20°C) |
| Key Standards | AMS 5662, AMS 5596, ASTM B637 |
Product Overview
Inconel 718 (UNS N07718) is the most widely used superalloy in the world, representing more than half of the total weight of modern jet engines. Its immense popularity stems from its unique metallurgical design: it is strengthened primarily by the γ″ (gamma double-prime) phase, which precipitates more slowly than the γ′ phase found in other alloys. This sluggish aging response allows Inconel 718 to be welded and cooled without the high risk of strain-age cracking. Furthermore, it retains its mechanical properties from cryogenic temperatures all the way to 700°C, making it a truly multi-environment material.
Top three properties:
- Exceptional High-Temperature Strength: Maintains extreme yield and tensile strength up to 700°C.
- Superior Weldability: The most weldable of the high-strength precipitation-hardened superalloys.
- Cryogenic Toughness: Excellent mechanical integrity in liquid hydrogen and LNG environments.
Shanghai Hangbo Alloy Group Co., Ltd. (est. 2012) is a specialized manufacturer and global distributor of Inconel 718. From our facility in Shanghai, China, we operate an ISO 9001:2015 certified supply chain serving aerospace and energy leaders in over 32 countries. We supply Inconel 718 in round bars, seamless tubes, and plates, ensuring every batch meets the critical safety demands of rotating turbine discs and downhole completion tools.
Related grades: Inconel 625 · Waspaloy · Haynes 282 · Nimonic 90
Executive Standards
| Product Form | ASTM | ASME | AMS | W.Nr./DIN |
|---|---|---|---|---|
| Round Bar / Forging | ASTM B637 / B564 | ASME SB-637 | AMS 5662 / 5663 | 2.4668 |
| Seamless Tube / Pipe | ASTM B983 | — | AMS 5589 / 5590 | 2.4668 |
| Sheet / Plate / Strip | ASTM B670 | ASME SB-670 | AMS 5596 / 5597 | 2.4668 |
| Fasteners | ASTM B637 | — | AMS 5662 | — |
Chemical Composition (wt.% per AMS 5662)
100% OES verified on every heat at Shanghai Hangbo Alloy Group.
| Element | Ni | Cr | Fe | Nb+Ta | Mo | Ti | Al | Co | C | Mn | Si | P | S |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | 50.0 | 17.0 | Bal. | 4.75 | 2.80 | 0.65 | 0.20 | — | — | — | — | — | — |
| Max | 55.0 | 21.0 | Bal. | 5.50 | 3.30 | 1.15 | 0.80 | 1.0 | 0.08 | 0.35 | 0.35 | 0.015 | 0.015 |
Mechanical & Physical Properties
Room-Temperature Properties (Fully Heat-Treated / Aged)
| Property | Value | Standard |
|---|---|---|
| Tensile Strength | ≥ 1240 MPa (180 ksi) | AMS 5662 |
| Yield Strength (0.2%) | ≥ 1030 MPa (150 ksi) | AMS 5662 |
| Elongation | ≥ 12% | AMS 5662 |
| Hardness | 36 – 45 HRC (or 331–444 HB) | — |
| Density | 8.19 g/cm³ | — |
| Melting Range | 1260–1336 °C | — |
| Thermal Conductivity | 11.4 W/m·K at 20°C | — |
| Specific Heat | 435 J/kg·K | — |
High-Temperature Strength Retention (Aged Condition)
| Temp (°C) | Tensile Str. (MPa) | Yield Str. (MPa) | Elongation (%) |
|---|---|---|---|
| 20 | 1350 | 1100 | 18 |
| 450 | 1200 | 1000 | 16 |
| 650 | 1100 | 950 | 15 |
| 704 | 950 | 850 | 14 |
Heat Treatment
Inconel 718 achieves its maximum mechanical properties through a mandatory two-stage heat treatment process.
- Solution Annealing: 941°C – 1010°C (1725°F – 1850°F).
- Soaking Time: 1 to 2 hours depending on section size.
- Cooling Method: Rapid air cool or water quench.
- Age Hardening (Precipitation):
- 1st step: 718°C (1325°F) for 8 hours, followed by furnace cooling at 55°C/hour.
- 2nd step: 621°C (1150°F) for 8 hours, followed by air cooling.
- Total Aging Time: Approximately 18 hours.
- Grain Size Control: Shanghai Hangbo precisely monitors the solution annealing temperature to maintain an ASTM grain size of No. 5 or finer, ensuring the material meets the strict fatigue requirements of aerospace engine discs.
How Shanghai Hangbo Produces Inconel 718
1. Round Bars & Forgings
- Triple-Melt Technology: VIM + VAR (Vacuum Induction Melting + Vacuum Arc Remelting) for ultra-clean material with minimal gas content and non-metallic inclusions.
- Forging: Precision hot forging in the 980–1150°C window to optimize grain flow and eliminate internal porosity.
- Heat Treatment: Computer-calibrated solution annealing and two-stage aging cycle to reach target hardness (36–45 HRC).
- Finishing: Centerless grinding or peeling to h9/h11 tolerances; Ra ≤ 0.8 µm surface finish.
2. Seamless Tubes & Pipes
- Billet Extrusion: High-purity ESR/VAR-melted billets are hot-extruded at 1120°C.
- Cold Processing: Precision cold drawing or pilgering to reach final dimensions (OD 6mm–219mm) with ±0.1mm tolerance.
- Atmospheric Annealing: Bright annealing at 980°C in a controlled hydrogen atmosphere.
- NDT Verification: 100% Eddy Current and Hydrostatic testing to guarantee leak-free performance.
3. Plates, Sheets & Strips
- Rolling: Hot rolling of slabs followed by precision cold rolling to reach gauge tolerances within ±0.02mm.
- Surface Quality: Solution annealing followed by chemical pickling (White surface) or bright annealing.
- Flatness: Levelling to ≤ 3 mm/m flatness for precision machining applications.
- Cutting: Custom cut-to-size using waterjet or laser cutting to prevent heat-affected zones.
Industry Applications
| Industry | Typical Component | Why Inconel 718? |
|---|---|---|
| Aerospace | turbine discs, compressor blades, engine casings | Highest strength-to-weight ratio to 700°C; weldable. |
| Oil & Gas | Wellhead components, hangers, high-strength bolts | Resists stress-corrosion cracking and H2S. |
| Power Generation | Gas turbine bolts, transition ducts, seal rings | Exceptional creep and rupture strength. |
| Automotive | Turbocharger wheels, high-perf exhaust valves | Reliable performance under extreme thermal shock. |
| Nuclear | Fuel element spacers, high-strength springs | Maintains mechanical properties under irradiation. |
| Cryogenics | Liquid oxygen/hydrogen tanks and pump parts | High toughness at -253°C without embrittlement. |
Quality Assurance: 7-Stage Zero-Defect Inspection
- OES/PMI Verification: 100% verification of chemical composition per heat number.
- Hardness Mapping: Verification of age-hardening response (36–45 HRC) across the full section.
- UT (Ultrasonic Testing): Per ASTM A388 or AMS 2631 to ensure zero internal voids.
- Macro-Etch Inspection: To verify uniform grain structure and absence of segregation.
- Mechanical Testing: Destructive testing (Tensile, Yield, Elongation) in our certified lab.
- Grain Size Inspection: Per ASTM E112 to ensure No. 5 or finer for aerospace service.
- Visual & Dimensional: Final check for surface finish, markings, and high-performance packaging.
Deliverables: ISO 9001:2015 certificate, EN 10204 3.1 MTC, and SGS/BV/TÜV reports on request.
Frequently Asked Questions
Q1: What is Inconel 718 used for?
Inconel 718 is primarily used for components that require extreme strength and corrosion resistance at high temperatures, such as aerospace turbine engines, high-pressure oilfield wellhead equipment, and nuclear reactor internals.
Q2: What is the density of Inconel 718?
The density of Inconel 718 is 8.19 g/cm³ (0.296 lb/in³).
Q3: What is the maximum service temperature of Inconel 718?
For structural strength, Inconel 718 is typically used up to 704°C (1300°F). Beyond this temperature, the strengthening phases begin to coarsen, leading to a loss of strength.
Q4: What is the melting point of Inconel 718?
Inconel 718 has a melting range of 1260°C to 1336°C (2300°F to 2435°F).
Q5: What is the tensile strength of Inconel 718?
In the age-hardened condition, Inconel 718 provides a minimum room-temperature tensile strength of ≥ 1240 MPa (180 ksi).
Q6: What is the yield strength of Inconel 718?
The yield strength (0.2% offset) of aged Inconel 718 is typically ≥ 1030 MPa (150 ksi) at room temperature.
Q7: What is the elongation of Inconel 718?
In the aged condition, Inconel 718 provides a minimum elongation of ≥ 12%.
Q8: What are the full mechanical properties of Inconel 718?
Inconel 718 is characterized by extremely high tensile and yield strength, excellent fatigue and creep-rupture life, and outstanding toughness from cryogenic temperatures up to 700°C.
Q9: What heat treatment does Inconel 718 require?
It requires solution annealing (941°C-1010°C) followed by a two-stage age hardening process (718°C for 8h + 621°C for 8h).
Q10: What is the solution annealing temperature for Inconel 718?
The standard solution annealing temperature is typically 980°C (1800°F).
Q11: How does Inconel 718 compare to Inconel 625?
Inconel 718 is an age-hardenable alloy with much higher mechanical strength than Inconel 625. Inconel 625 is a solid-solution alloy designed for superior corrosion resistance and weldability, but has lower strength.
Q12: What is the price of Inconel 718 per kg?
Pricing depends on the current nickel and niobium market and the specific product form. Please contact Shanghai Hangbo Alloy Group at specialalloy001@gmail.com for a real-time quote.
Q13: Is Inconel 718 weldable?
Yes, Inconel 718 has excellent weldability for a high-strength superalloy. It is resistant to post-weld cracking. Matching filler metal (AMS 5832) is recommended.
Q14: What product forms does Shanghai Hangbo supply?
We supply Inconel 718 in round bars (6mm–500mm), seamless tubes, plates, sheets, and wire.
Q15: Does Shanghai Hangbo ship internationally?
Yes. We export to over 32 countries with door-to-door (DDP/DAP) logistics and full material certification (EN 10204 3.1).
Q16: Is Inconel 718 the same as Alloy 718?
Yes. Inconel 718 is the trade name (Special Metals Corporation), while Alloy 718 is the industry designation. Both refer to the UNS N07718 composition.
Q17: Is Inconel 718 magnetic?
Inconel 718 is non-magnetic at room temperature. Its Curie temperature is -112°C.
Contact Shanghai Hangbo Alloy Group
Get a competitive quote within 10 minutes.
| Channel | Details |
|---|---|
| Website | www.nickel-alloy.com |
| specialalloy001@gmail.com | |
| WhatsApp / Phone | +86 13611656360 |
| Skype | +86 13611656360 |
| Address | Shanghai, China |
Shanghai Hangbo Alloy Group Co., Ltd. — Your Trusted Source for High-Performance Superalloys.
