Bar and Rod
Plate and Sheet
Strip
Pipe and Tube
Wire
Welding
Powder Material
Cast Products
Forged Products
Fittings
Fastening
Round Bar:
φ2–500 mm, 1–6 m length
Flat/Square Bar:
4–100 mm thickness/width
Hex Bar:
A/F 3–100 mm
Hollow Bar:
OD 20–300 mm
Sheet:
0.3–6 mm thickness
Medium Plate:
6–25 mm thickness
Heavy Plate:
25–100 mm thickness
Standard Strip:
0.05–3 mm thick,
10–600 mm wide
Precision strip:
0.01–0.5 mm thick,
tight tolerance ±0.005 mm
Foil:
0.005–0.1 mm thick
Seamless Tube:
OD 6–450 mm,
WT 1–50 mm,
1–12 m length
Welded Tube:
OD 10–600 mm,
WT 1–20 mm
Capillary Tube:
OD 1–10 mm,
WT 0.1–2 mm
Wire Form:
Cold Drawn Wire,
Bright Wire,
Spring Wire,
Fine Wire,
Ultra-fine Wire
General Diameter:
φ0.1–10 mm
Coil Weight:
50–500 kg,
customizable tolerance
Solid Wire:
φ0.8–4.0 mm
Flux-cored Wire:
φ1.2–4.0 mm
Welding Rod:
φ2.0–5.0 mm
Powder Form:
AM 3D Printing Powder,
Spherical Powder,
Gas-atomized Powder,
Water-atomized Powder
Particle Size:
10–150 μm
Sphericity:
≥90% for AM grade
Cast Ingot:
φ200–800 mm
Precision Casting:
min wall 0.5 mm
Cast Pipe:
OD 100–600 mm,
WT 10–50 mm
Forged Bar:
Φ35–500 mm
Forged Ring:
OD 200–2000 mm
Forging Weight:
1–5000 kg
Fittings Form:
Elbow, Tee, Reducer, Flange, Cap, Outlet, Lap Joint
Size range:
1/2''–24'' (DN15–DN600)
Wall thickness:
Sch10–Sch160, STD, XS, XXS
Pressure Class:
150–2500 LB
Fastening Form:
Bolt, Nut, Screw, Stud, Washer, Pin, Rivet
Metric: M3–M64
Imperial: #4–2.5''
Length: 6–500 mm
Alloy 718 is a precipitation-hardenable nickel-chromium-iron superalloy and one of the most widely used superalloys in the world. This datasheet presents the material within the American (ASTM / ASME / UNS) standard system.
Developed in the 1960s as an age-hardenable derivative of alloy 625, Alloy 718 derives its outstanding strength from the precipitation of gamma-prime (γ′, Ni₃(Al,Ti)) and gamma-double-prime (γ″, Ni₃Nb) phases during ageing, with niobium the key strengthening addition. It combines high tensile, fatigue, creep and stress-rupture strength up to about 700 °C (1300 °F) with good oxidation resistance to about 980 °C, excellent cryogenic toughness, and good weldability and fabricability — the latter notably better than many γ′-only superalloys because the sluggish γ″ response resists strain-age cracking. It is non-magnetic and is used in the solution-treated and aged condition.
Typical applications include gas-turbine discs, blades, casings and combustor components, aero-engine and rocket-engine parts, oil-and-gas downhole and wellhead equipment, fasteners, and cryogenic hardware.
| Property | Value | Unit |
|---|---|---|
| Density | 8.19 | g/cm³ |
| Melting range | 1260–1336 | °C |
| Elastic modulus | 200 | GPa |
| Coefficient of thermal expansion (20–100 °C) | 13.0 | µm/m·°C |
| Thermal conductivity (20 °C) | 11.4 | W/m·K |
| Specific heat (20 °C) | 435 | J/kg·K |
| Structure | Austenitic (FCC) | — |
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Nickel | Ni | 50.0 | 55.0 | Austenite former; γ′/γ″ matrix |
| Chromium | Cr | 17.0 | 21.0 | Oxidation / corrosion resistance |
| Iron | Fe | Balance | — | Base element (~18%) |
| Niobium | Nb (+Ta) | 4.75 | 5.50 | γ″ (Ni₃Nb) precipitation strengthening |
| Molybdenum | Mo | 2.80 | 3.30 | Solid-solution strengthening |
| Titanium | Ti | 0.65 | 1.15 | γ′ (Ni₃Ti) precipitation strengthening |
| Aluminium | Al | 0.20 | 0.80 | γ′ formation |
| Cobalt | Co | — | 1.00 | Residual |
| Carbon | C | — | 0.08 | Carbide formation |
| Manganese | Mn | — | 0.35 | Deoxidiser |
| Silicon | Si | — | 0.35 | Deoxidiser |
| Boron | B | — | 0.006 | Grain-boundary strengthening |
| Copper | Cu | — | 0.30 | Residual |
Solution-treated and aged condition, typical values for UNS N07718.
| Condition | Property | Value |
|---|---|---|
| Solution treated & aged | Tensile strength (UTS) | ≥1240 MPa (180 ksi) |
| Solution treated & aged | 0.2% yield strength | ≥1035 MPa (150 ksi) |
| Solution treated & aged | Elongation at break | ≥12 % |
| Solution treated & aged | Reduction of area | ≥15 % |
| Solution treated & aged | Hardness | ~36–44 HRC |
Confirm against the mill test report. Properties depend on the solution and double-ageing treatment selected.
| Environment | Performance | Notes |
|---|---|---|
| High-temperature oxidation | Very Good | To about 980 °C |
| Aqueous / general | Good | Chromium + molybdenum bearing |
| Sour gas (H₂S) | Good | Qualified to NACE MR0175 (per condition) |
| Chloride pitting / crevice | Good | Mo-bearing |
| Elevated-temperature strength | Excellent | Primary design advantage |
Corrosion and oxidation resistance is good for its class; the alloy is selected primarily for its exceptional combination of high strength, fatigue and creep resistance with adequate corrosion resistance.
A precipitation-hardenable superalloy; strengthened by solution treatment followed by double ageing.
Solution Treatment Solution anneal at approximately 950–1010 °C and cool (air or faster). A higher solution temperature (~1040–1065 °C) is used where creep-rupture performance is prioritised.
Precipitation Hardening (Ageing) Age in two steps — approximately 720 °C / 8 h, furnace cool to about 620 °C, hold ~8 h, air cool — precipitating γ′ (Ni₃(Al,Ti)) and γ″ (Ni₃Nb). The double-age schedule develops the standard high-strength condition.
Good weldability, notably better than many γ′-strengthened superalloys owing to the sluggish γ″ ageing response, which resists strain-age cracking. Welding is done in the solution-annealed condition with post-weld heat treatment.
| Welding Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG | Good | Matching alloy 718 filler (ERNiFeCr-2) |
| GMAW / MIG | Good | Matching filler |
| EBW / laser | Good | Autogenous or matching filler |
Weld in the solution-annealed condition; apply post-weld solution and ageing to develop properties.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Preferred condition | Solution-annealed for machining, then age |
| Machinability | Difficult; rigid setups, carbide tooling, slow speeds |
| Coolant | Ample coolant |
Forming Processes
| Process | Notes |
|---|---|
| Cold forming | In the annealed condition; work-hardens rapidly |
| Hot forming | Readily forged; solution and age afterward |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Aero gas turbine | Discs, blades, casings, combustors | Strength + fatigue + creep to ~700 °C |
| Rocket / space | Engine components, hardware | Strength + cryogenic toughness |
| Oil & gas | Downhole and wellhead equipment | Strength + sour-service resistance |
| Industrial | Fasteners, springs, high-temperature parts | Strength + fabricability |
| Product Form | ASTM Standard | AMS |
|---|---|---|
| Bar, forgings and rings | ASTM B637 | AMS 5662 / 5663 / 5664 |
| Sheet, plate and strip | ASTM B670 | AMS 5596 / 5597 |
| Wire | ASTM B637 | — |
| Sour-service / oilfield | API 6A718 | NACE MR0175 |
Nickel-chromium-iron precipitation-hardenable superalloy. UNS N07718.
| Alloy | Ni % | Strengthening | Max Temp | Best Used For |
|---|---|---|---|---|
| Alloy 718 | 50–55 | γ′ + γ″ (Nb, Ti) | ~700 °C | Most-used superalloy; turbine discs, aero, oil & gas |
| Alloy 706 | 39–44 | γ′ + γ″ (Nb, Ti) | ~705 °C | 718-type strength, better fabricability; large discs |
| Alloy 725 | 55–59 | γ′ + γ″ (Nb, Ti) | ~700 °C | Age-hardened 625; sour-service corrosion + strength |
| Alloy X-750 | ≥70 | γ′ (Al, Ti) | ~815 °C | Springs, bolts, high-temperature fasteners |
| Alloy 625 | ≥58 | Solid solution | ~815 °C | Corrosion + moderate high-temperature strength |
+86 021 3355 6635
+86 133 7189 7780
zcalloy1001@gmail.com
Building E265, No. 2, Lane 158, Gangye Road, Xiaokunshan Town, Songjiang District, Shanghai
