Nimonic Alloy 75 is a robust, solution-strengthened nickel-chromium superalloy that delivers excellent oxidation and scaling resistance with moderate high-temperature strength and very good fabricability; it is ideal for furnace parts, gas-turbine ancillary components and engineered sheet/plate applications where oxidation resistance and formability matter more than maximum creep strength.
What is NIMONIC 75?
Nimonic 75 (UNS N06075; EN 2.4630 / 2.4951; trade names include Nimonic® 75, Alloy 75, Haynes 75 in some sources) is a nickel-chromium base alloy originally developed in the 1940s for early jet-engine/turbine components. It is an "80/20" Ni–Cr family member with controlled titanium and carbon additions that provide modest strengthening and improved oxidation resistance. The alloy is primarily used in sheet, strip and forged forms for components that run hot in oxidizing atmospheres but do not require the highest creep/rupture strength of age-hardenable superalloys.
Chemical composition
The table below compiles commonly published composition ranges for Nimonic 75 and Nimonic 80A (wt. %). These are typical composition windows used by producers-always confirm with your supplier certificate (CoA) for a batch-specific analysis.
| Element | Nimonic 75 (typical wt.%) | Nimonic 80A (typical wt.%) |
|---|---|---|
| Nickel (Ni) | Balance (~≥70–78%) | Balance (~≥70–78%) |
| Chromium (Cr) | 18.0 – 21.0 | 18.0 – 21.0 |
| Iron (Fe) | ≤ 5.0 | ≤ 5.0 |
| Titanium (Ti) | 0.6 – 1.2 | 0.6 – 1.4 |
| Aluminium (Al) | trace–0.6 | 0.6 – 1.2 |
| Carbon (C) | 0.08 – 0.15 | 0.05 – 0.15 |
| Manganese (Mn) | ≤1.0 | ≤1.0 |
| Silicon (Si) | ≤1.0 | ≤1.0 |
| Copper (Cu) | trace | trace |
| Other (Co, Nb etc.) | trace levels | trace levels |
Material properties
| Property | Typical value / range |
|---|---|
| Density | 8.37 g·cm⁻³ (8370 kg·m⁻³) |
| Melting range | ≈ 1340–1380 °C |
| Tensile strength (annealed) | ~700–850 MPa (published ranges vary by product form) |
| Yield strength (annealed) | ~285–445 MPa (depending on temp and form) |
| Elongation (in 50 mm) | ~30–40% (good ductility in annealed condition) |
| Hardness | Moderate; can be strain-hardened; Rockwell and BHN vary by temper. |
| Typical service temperature | up to ~600–700 °C for continuous service; short excursions higher. |
| Oxidation resistance | Excellent in oxidizing atmospheres up to ~1000 °C (surface scaling low compared to many steels). |
| Fabricability | Excellent formability and weldability when annealed - commonly used in sheet forming. |
Standards and designations
UNS N06075 - universal (UNS) identifier.
EN / W.Nr. 2.4630 and 2.4951 - European material numbers reported in datasheets; EN designation often appears as NiCr20Ti.
Trade names / suppliers: Nimonic® 75 (Special Metals), Haynes® 75 (Haynes International / alternative formulation), ATI-75, Alloy 75, Nicrofer 7520 (some supplier labels). Always confirm the producer's MTC and exact spec.
What is Nimonic 75 used for?
Because of its unique balance of oxidation resistance, reasonable high-temperature strength, and good formability, Nimonic 75 is typically chosen for:
Gas turbine ancillary parts (casings, shrouds, combustion supports) where oxidation scaling is a concern but ultimate creep strength is not the primary driver.
Industrial furnace components and heat-treatment fixtures where repeated exposure to oxidizing atmospheres and thermal cycling occurs.
Aerospace fabricated components (sheet-formed parts, fasteners in some niches) where welding and forming plus temperature resistance are needed.
Nuclear and laboratory high-temperature equipment requiring stable surfaces under long-term oxidation.
The alloy's formability (sheet/strip) and weldability make it economical in manufacturing relative to age-hardenable superalloys that often need complex heat treatments.
What is equivalent to NIMONIC 75?
Haynes® 75 / ATI-75 / Alloy 75 - commercially comparable compositions and performance in datasheets.
EN NiCr20Ti / 2.4630 - the European designation often used for engineering procurement.
Some references compare Nimonic 75 to Alloy 600 in certain oxidation aspects, but Nimonic 75 has Ti and slightly different balance, so substitution requires care.
Heat treatment, forming and welding
Annealing / solution treatment: common practice is ~1050–1052 °C for short soak times (sheet: 5–10 min; bar: 30–60 min) then air cooling - this produces an annealed, ductile condition recommended before forming and welding.
Hot working ranges: ~1220–950 °C (recommended hot-work window) with appropriate cooling/quenching depending on downstream processing.
Cold working / hardening: the alloy work-hardens; many strength increases are achieved by cold deformation rather than precipitation hardening. Spring temper may be achieved through cold work plus stress relief (typical stress-relief ~450–470 °C for 0.5–1 hr).
Welding: weldable with common Ni-based filler metals when the parent is annealed; parts are normally annealed before welding to avoid cracking from prior cold work. Use matching filler and follow qualified welding procedures for service temperature and pressure requirements.
Inspection notes: watch for grain growth during high-temperature cycles and for any carburisation/scale on surfaces operating in contaminated atmospheres - post-weld heat treatment and chemical analysis of critical lots is recommended.
Practical difference: Nimonic 75 vs Nimonic 80A
Both are members of the Nimonic family but differ in emphasis:
Nimonic 75: solution-strengthened Ni–Cr with Ti/C additions; emphasizes oxidation resistance, formability and moderate strength up to ~600–700 °C. Good for sheet parts and furnace applications.
Nimonic 80A: typically higher strength and creep resistance due to different chemistry (higher Al/Ti or other strengthening elements in certain variants) and sometimes heat-treatable features; better where higher long-term stress at elevated temperatures is required but with somewhat reduced ductility/formability.
Our product range
Our company specializes in the export of high-performance nickel-based alloys and special metal materials, offering a product line that covers diverse industrial applications such as high-temperature, corrosion-resistant, and high-strength scenarios. Our core products include nickel-based superalloys like Hastelloy, Inconel, and Incoloy, as well as super austenitic stainless steels, duplex steels, Monel alloys, cobalt-based alloys, and precision alloy series. These materials deliver exceptional performance under extreme conditions-such as high temperatures, strong corrosion, and high pressure-and are widely used in aerospace, energy and chemical engineering, marine engineering, and high-end equipment manufacturing. We provide global clients with reliable material solutions and technical support.
Our factory
Our factory is equipped with an advanced system of production and testing equipment, enabling full-process manufacturing capabilities from smelting and hot working to precision finishing. At the core of production, we utilize vacuum induction melting (VIM) and electroslag remelting (ESR) furnaces to ensure high purity and uniform composition of alloy materials. We also employ multi-directional forging presses, precision rolling mills, and continuous annealing lines to achieve precise forming of plates, tubes, bars, and wires. Quality assurance relies on testing equipment such as direct-reading spectrometers, scanning electron microscopes (SEM), high-temperature mechanical testing machines, and corrosion test chambers, which rigorously monitor compositional structure, mechanical properties, and corrosion resistance. Adhering to international standards such as ISO, ASTM, and ASME, our factory implements an intelligent management and control system throughout the entire production process, delivering high-performance, traceable premium alloy products to our clients.
