Nimonic Alloy 80A is a precipitation-hardenable nickel-chromium superalloy engineered for sustained high-temperature strength and oxidation resistance up to about 815°C (1500°F); it is widely used for gas-turbine parts, high-temperature fasteners and nuclear components where low cobalt and excellent creep resistance are required.
What is Nimonic 80A?
Nimonic 80A is a wrought, age-hardenable nickel-chromium alloy strengthened by additions of titanium and aluminium (and small controlled carbon). It was developed for components that operate under continuous stress at elevated temperatures, offering a balance of tensile strength, creep-rupture resistance and oxidation stability in the ~500–815°C service window. The material is produced in vacuum-refined and conventional melt forms and is supplied in bars, rods, plate, wire and forgings.
Key material properties
Below are widely reported engineering properties for condition-dependent temper (age-hardened). Numbers vary with heat treatment and product form — cite material supplier datasheets for procurement acceptance testing.
Property | Typical value (age-hardened / annealed ranges) |
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Density | ≈ 8.19 g/cm³ (≈ 0.296 lb/in³) |
Tensile strength (UTS) | ~650–820 MPa depending on condition (sheet/rod/age) |
Yield strength (0.2% proof) | ~350–430 MPa (heat treated variations) |
Creep/rupture capability | Designed for long-term load at up to ≈815°C (1500°F); excellent creep resistance relative to many Ni-base alloys of its era. |
Melting / solidus range | ~1320–1365°C (typical reported range) |
Specific gravity | ≈ 8.1–8.2 |
Oxidation resistance | Good at elevated temperatures; used in turbine and exhaust environments. |
Note: property tables from manufacturers (Special Metals, Carpenter, Smiths, etc.) include detailed temperature-dependent creep and rupture charts. Always use the supplier’s certified test data for design calculations.
Chemical composition (typical / approximate — wt %)
The following table provides typical composition bounds used in product datasheets and standards. Always verify with mill certificates for the batch you buy.
Element | Typical (wt %) — Nimonic 80A (UNS N07080) |
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Nickel (Ni) | ~50.0–60.0 (major balance) |
Chromium (Cr) | ~19–21 |
Titanium (Ti) | ~2.5–3.0 (precipitation strengthening) |
Aluminium (Al) | ~1.0–1.6 (γ′ former) |
Carbon (C) | ~0.06–0.15 (controlled) |
Iron (Fe) | ≈ 6–8 (residual) |
Manganese (Mn), Silicon (Si), Sulfur (S), Phosphorus (P) | Trace to small residual amounts per spec limits. |
(If your procurement requires EN/ASTM exact limits, request the standard mill specification / material test report for confirmation.)
Standards and specifications
Common designation cross-references you will see on documentation and purchase orders:
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UNS N07080 (United States Numbering System).
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W. Nr. 2.4952 / 2.4631 (European/Werkstoff numbers appear in supplier material sheets).
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ASTM B637 is often referenced for forged/rolled products (check the exact product form and spec clause).
Typical applications and why engineers pick 80A
Practical fields of use:
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Gas turbine components (blades, discs, rings for certain low-cobalt designs).
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High-temperature fasteners and bolts that need low creep at elevated temperatures.
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Nuclear steam-generator internal supports and tube-support components where low cobalt is favorable.
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Exhaust valves and hot springs in automotive/aerospace niches requiring sustained springback.
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Die casting inserts and cores due to combination of hot hardness and oxidation resistance.
Designers choose 80A when a precipitation-hardenable Ni-Cr alloy with good long-term creep resistance and relatively low cobalt is desirable.
Is NIMONIC 80A better than Inconel 625?
Short practical comparison:
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Inconel 625 is a nickel-chromium-molybdenum-niobium alloy optimized for corrosion resistance (pitting, chloride) and high strength without precipitation-hardening; it is often the go-to when corrosion resistance in aggressive environments is the priority.
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Nimonic 80A is precipitation-hardenable (Ti/Al) and tuned for high temperature tensile and creep performance at sustained temperatures up to ~815°C; it was developed for creep resistance and turbine service.
Rule of thumb: pick 80A for high-temperature structural parts and springs where creep resistance and low cobalt are required; pick 625 for severe corrosion environments or when welded, solid-solution strength without ageing is preferred. For direct substitution always check mechanical properties at operating temperature and the environmental exposure.
What is alloy 80A equivalent to?
Common cross-references / equivalents provided by suppliers and mills:
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UNS N07080
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W. Nr. 2.4952 / 2.4631 (depending on source/doc type).
Some manufacturers sell proprietary or closely equivalent grades (for example GH4080A in Chinese catalogs) — but equivalence must be confirmed by chemical limits and mechanical data.
Heat treatment and ageing
Nimonic 80A obtains its high-temperature properties via a solution treatment followed by controlled ageing to precipitate γ′ (Ni₃(Al,Ti)) particles.
Typical schedules reported in supplier datasheets (illustrative; use mill sheet for warranty conditions):
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Solution treat: ~1080–1150°C, air cool (exact time depends on product form).
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Ageing / precipitation: commonly 700–850°C for several hours (combinations such as 8 h at 1080°C then 16 h at 700°C appear in manufacturer examples).
Welded assemblies typically require solution treatment and post-weld ageing to restore creep performance; some thin sheet products use rapid interstage annealing cycles in production. For precise cycles and mechanical results consult the alloy technical bulletin from the mill.
Difference between Nimonic 80A and Nimonic 90
Briefly:
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Nimonic 90 is a later development with different alloying balance (often higher strength and modified γ′ chemistry) and is sometimes preferred for newer turbine designs and higher-temperature creep performance. 80A historically preceded 90 and remains specified in legacy and certain low-cobalt nuclear components. For a direct engineering substitution check both composition and creep/rupture charts from the supplier.
Fabrication, welding and machinability notes
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Hot work: recommended hot-working range ≈ 1050–1200°C; hot forging and extrusion are common.
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Cold work: limited — work hardening occurs and subsequent heat treatment required to regain properties.
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Welding: TIG/MIG methods are used with matched filler metals; recommended procedure often includes solution treat + age to restore parent-metal creep behavior. Fillet/weld procedures must follow qualified welding procedure specifications.
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Machinability: moderate; better than some cast superalloys but slower than stainless steels — typical cutting speeds and coolant strategies should follow supplier guidance.
Size & weight reference
Below is a simplified reference for common bar and plate forms. For design mass estimation use the exact measured dimensions.
Form | Typical sizes available | Approx. density (used) |
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Round bar | Ø 6 mm — Ø 150 mm (metric) and custom forgings | 8.19 g/cm³ |
Plate / sheet | 0.5 mm — 25 mm+ (cut to order) | 8.19 g/cm³ |
Wire / rod | Cold drawn wires in spring grades | 8.19 g/cm³ |
Example quick weight rule: 1 m of Ø20 mm round bar ≈ 2.58 kg (using density 8.19 g/cm³). For accurate mass lists produce CAD BOMs and request certified mill test reports.
Nimonic 80A Price 2025 (USD / kg)
Region | Typical supply forms | Indicative 2025 price range (USD/kg) | Notes / caveats |
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China (factory / export) | Bars, rods, plate, forgings (factory lots) | US$30 – 50 / kg | Typical factory quotations from Chinese mills / trading houses for small-to-medium lots; verify MTC and processing. |
China — online / marketplace listings | Small parts, samples, cut-to-size pieces | US$15 – 46 / kg (platform/listing prices) | Many B2B platform listings; low figures often reflect sample cuts, non-vacuum product or unverified listings — always request mill certificates. |
Europe (manufacturers / distributors) | Plate, bar, machined forgings | US$50 – 120 / kg | Wide band: depends on certification level, certification body, and form. EU-sourced certified stock tends to sit in the upper half. |
North America (distributors / certified stock) | Round bar, plate, aerospace/nuclear certified pieces | US$85 – 130 / kg | Distributor inventory and small certified batches command premiums (inspection, lot testing, small MOQ). |
Aerospace / nuclear / small certified lots (global) | Small batches with full traceability & testing | US$100 – 180+ / kg (project-dependent) | Highest premiums when EN/AS/AMS/3.2/3.1 certs, NDT, and bespoke heat-treatment reports are required. |
Key notes
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These are indicative ranges for budgeting. Final prices depend on alloy feedstock, market surcharges, product form, certification level, quantity and payment/shipping terms.
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Verify certificates: Many very low online listings do not include proper mill test certificates (MTC). Always request UNS/EN designation and MTC (EN 10204 3.1 / 3.2) for critical purchases.
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Certification & traceability cost more: Aerospace, nuclear or AMS-specified material will be priced materially higher than commodity industrial stock.
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Order volume matters: Per-kg cost falls with tonnage; small-sample or cut-to-size orders can double or triple the per-kg price versus bulk.
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Use RFQ details: When requesting quotes, specify UNS N07080 (or W.-Nr./EN cross-ref), required heat treatment state, acceptance tests, quantity, and destination port — that avoids ambiguous or misleading prices.
Supply, lead times, quality assurance — MWAlloys proposition
MWAlloys supplies Nimonic 80A bar, rod, sheet and forgings from our China production network. Key points we provide for global buyers:
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Factory pricing: 100% factory direct quotes on standard forms and OEM lots.
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Inventory & fast dispatch: we keep a rotating stock of common diameters and plate sizes; typical lead times for stocked items can be shorter than buying through tiered distributors (confirm at RFQ).
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Certification: full mill test reports (chemical & mechanical), traceability (UNS / WNR / EN), and testing per buyer specification.
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Custom processing: forging, machining, and heat treatment/ageing to buyer schedules.
FAQs
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What maximum temperature can Nimonic 80A be used at?
Practical continuous service: about 815°C (1500°F); design limits depend on load and desired life. -
Is Nimonic 80A good for springs?
Yes — it has been used for high-temperature springs where ageing strengthens the alloy and springback is retained at elevated temperature. -
Can Nimonic 80A be welded?
Yes; TIG/MIG methods with matched filler are common, but solution treatment and post-weld ageing are often required to regain optimal creep resistance. -
Is 80A radiation-suitable for nuclear?
It has been used for certain nuclear steam-generator support components because of its low cobalt and acceptable high-temperature performance; follow nuclear procurement standards. -
What is the main strengthening mechanism?
Gamma-prime (γ′) precipitation (Ni₃(Al,Ti)) formed during ageing provides high temperature strength. -
Which tests should I request on delivery?
Chemical analysis, tensile at room temp (and elevated temp when required), hardness, and the relevant NDT (radiography, PT/UT) per purchase spec. -
Is Nimonic 80A superseded by newer alloys?
In some applications newer alloys (Nimonic 90, Inconel X-750, etc.) may offer advantages; however, 80A remains specified where legacy designs or low-cobalt requirements apply. -
How does heat treatment affect properties?
Solution treat + ageing schedules control γ′ size and volume fraction; longer ageing or different ageing temps trade strength against ductility. Mill technical bulletins give specific charts. -
Are there standard equivalents from Chinese mills?
Vendors often list GH4080A or similar grades as equivalent; always cross-check chemical and mechanical limits. -
What’s the procurement tip to control cost?
Buy larger batches, accept standard mill finishes, or consider near-net forgings; secure certified suppliers and lock in price via alloy surcharge mechanisms.