What is Nimonic 86?
Alloy description, the function of each alloying element, and one point on which many datasheets disagree.
Nimonic 86 is a wrought nickel-base high-temperature alloy. The 25% chromium content forms a protective Cr₂O₃ scale. The 10% molybdenum provides solid-solution strengthening and creep resistance. The cerium addition of approximately 0.03% is a reactive rare-earth element that improves adhesion between the oxide scale and the base metal, so the scale is less likely to spall when the part is heated and cooled repeatedly.
In comparative cyclic oxidation testing at 1050 °C ±10 °C, on a cycle of 15 minutes at temperature followed by 5 minutes cooling in air, Nimonic 86 recorded a lower spalling rate and a longer time to oxide breakaway than both Nimonic 75 and Inconel alloy HX.
Nimonic 86 is not an age-hardening alloy
Nimonic 86 is a solid-solution alloy and cannot be age hardened. A number of stockist and trading websites list a solution treatment followed by an ageing cycle for Alloy 86, and some quote an ageing temperature near 860 °C. Those figures belong to the precipitation-hardening grades such as Nimonic 80A and Nimonic 90 and do not apply to this alloy. The correct treatment for Alloy 86 is a single solution anneal at 1150 °C.
Designations and specifications
| Designation type | Reference |
|---|---|
| Trade name | NIMONIC alloy 86 (Special Metals Corporation) |
| Common short names | Nimonic 86, Nimonic86, Alloy 86, Nickel alloy 86 |
| Chemical designation | NiCr25Mo10Ce |
| Aerospace specification, bar | MSRR 7141 |
| Aerospace specification, sheet | MSRR 7152 |
| Alloy family | Nickel-chromium-molybdenum, solid-solution strengthened |
Where a project specification calls for a national or aerospace designation not listed above, state it on the enquiry and it will be confirmed against the mill certificate before order. Designation and property data on this page are taken from the Special Metals Corporation technical bulletin for NIMONIC alloy 86, publication SMC-101, and from published stockist datasheets. NIMONIC is a trademark of the Special Metals Corporation group of companies. Jiangyin Jiangnan Metal Co., Ltd. is an independent forging factory and is not affiliated with Special Metals Corporation.
Chemical composition of Nimonic 86
Nominal analysis in weight percent.
| Element | Nominal, wt % | Function in the alloy |
|---|---|---|
| Nickel (Ni) | Balance, approx. 65 | Austenitic matrix and phase stability at temperature |
| Chromium (Cr) | 25.0 | Forms the protective Cr₂O₃ scale; oxidation and scaling resistance |
| Molybdenum (Mo) | 10.0 | Solid-solution strengthening and creep resistance |
| Carbon (C) | 0.05 | Carbide formation and grain-boundary strengthening |
| Cerium (Ce) | 0.03 | Reactive element; improves oxide-scale adhesion under thermal cycling |
| Magnesium (Mg) | 0.015 | Deoxidation and sulphur control; hot workability |
Nominal composition per Special Metals Corporation bulletin SMC-101. Balance indicates that nickel predominates; other elements may be present in minimal quantities. Each heat is supplied with its own ladle and product analysis on the material certificate.
Mechanical properties of Nimonic 86
Typical tensile properties after the recommended solution anneal. Bar data is the relevant set for forgings.
| Test temperature, °C | 0.2% proof stress, MPa | Tensile strength, MPa | Elongation on 5.65√S₀, % |
|---|---|---|---|
| 300 | 251 | 692 | 49 |
| 500 | 243 | 661 | 54 |
| 700 | 239 | 557 | 56 |
| 850 | 173 | 319 | 69 |
| Test temperature, °C | 0.2% proof stress, MPa | Tensile strength, MPa | Elongation on 50 mm, % |
|---|---|---|---|
| 20 | 438 | 873 | 45 |
| 750 | 250 | 502 | 74 |
| 850 | 184 | 310 | 83 |
| 900 | 125 | 237 | 66 |
| 1050 | 44 | 98 | 50 |
Typical values from Special Metals bulletin SMC-101 for material after the recommended heat treatment. These are indicative properties and not guaranteed minima. Acceptance values for a specific forging are agreed at order stage and reported on the EN 10204 certificate for the heat supplied.
Tensile strength falls from 692 MPa at 300 °C to 98 MPa at 1050 °C. For a component carrying load at high temperature, section size should be established from creep-rupture data for the design load and design life rather than from the tensile tables above.
Physical properties of Nimonic 86
Density, thermal expansion and dynamic Young's modulus, for thermal stress and shrink-fit calculations on rings and sleeves.
Density: 8.54 Mg/m³ (8.54 g/cm³, 0.309 lb/in³) at room temperature.
| Temperature range, °C | Mean CTE, ×10⁻⁶/°C | Temperature, °C | Young's modulus, GPa |
|---|---|---|---|
| 20 to 100 | 12.7 | 20 | 210 |
| 20 to 200 | 12.8 | 100 | 206 |
| 20 to 300 | 13.1 | 200 | 201 |
| 20 to 400 | 13.5 | 300 | 195 |
| 20 to 500 | 13.9 | 400 | 189 |
| 20 to 600 | 14.1 | 500 | 183 |
| 20 to 850 | 15.5 | 600 | 176 |
| 20 to 1050 | 16.8 | 850 | 155 |
| n/a | n/a | 1050 | 138 |
Values per Special Metals bulletin SMC-101. Expansion values apply to fully heat-treated material; a variation of approximately ±5% can be expected with composition, processing history and product form.
How Jiangyin Jiangnan Metal forges Nimonic 86
Melting route, forging practice, heat treatment and the size range produced.
Melting and forging stock
Nimonic 86 forging stock is melted by the EAF + VOD + ESR route: electric arc furnace melting, vacuum oxygen decarburisation for carbon and gas control, then electroslag remelting to refine the ingot structure. Electroslag remelting reduces segregation and non-metallic inclusion content. This matters on a 25Cr-10Mo composition, because a segregated ingot works poorly under the press and produces ultrasonic indications that cannot be removed by machining.
Open-die forging and ring rolling
Alloy 86 has good hot workability. Like other high-chromium nickel alloys it has a narrower working temperature window than steel and work hardens quickly, so forging is carried out with controlled reheats and a controlled finishing temperature. This completes recrystallisation and keeps grain size uniform through the section, which in turn allows ultrasonic testing at fine sensitivity. Rings are produced either as seamless rolled rings or as forged and bored rings, depending on diameter, wall thickness and quantity.
Heat treatment
Nimonic 86 forgings are solution annealed for 2 to 4 hours at 1150 °C and air cooled. No ageing step is applied. Furnace charts are recorded and issued with the material certificate. Where a customer specification calls for a different soak time or cooling method, that cycle is used instead and stated on the certificate.
Service temperature ranges to avoid
Long holds between 500 °C and 600 °C should be avoided. In that range Alloy 86 can undergo carbide precipitation followed by recrystallisation. Cold work accelerates the effect and widens the temperature range over which it occurs, so the point applies to components that operate warm rather than hot.
Product forms and size range
| Product form | Typical range | Notes |
|---|---|---|
| Seamless rolled rings | OD 300 to 2500 mm | Ring rolled; height and wall per drawing |
| Forged rings and hollow forgings | OD up to 2500 mm | Forged and bored for short runs and heavy walls |
| Forged flanges | OD up to 1500 mm | Blind, weld neck, slip on and special profiles |
| Forged discs and blanks | Diameter up to 1200 mm | Solid or pre-bored |
| Forged shafts and spindles | Length up to 6000 mm | Stepped or plain; eccentric shafts on request |
| Forged round bars | Diameter 50 to 500 mm | Peeled, turned or black as required |
| Sleeves, bushings and tube sheets | Per drawing | Bored, rough machined or finish machined |
| Valve components | Per drawing | Bodies, seat rings, stems and blocks for high-temperature service |
Ranges above are indicative. Send the drawing and Jiangyin Jiangnan Metal will confirm the achievable size, single-piece weight and lead time for the part.
Testing, inspection and certification
The document pack supplied with every Nimonic 86 forging.
- Chemical analysis. Ladle and product analysis reported per heat.
- Mechanical testing. Tensile and elongation at room temperature; elevated-temperature tensile, impact and hardness where the specification calls for it.
- Ultrasonic testing. To EN 10228-3, SEP 1921 or ASTM A388, at the acceptance class agreed at order stage.
- Surface NDT. Dye penetrant inspection on request. Magnetic particle testing does not apply, as Nimonic 86 is non-magnetic.
- Dimensional report. Against the customer drawing.
- Heat treatment record. Furnace charts for the solution anneal.
- Material certificate. EN 10204 3.1 as standard, or EN 10204 3.2 with third-party endorsement by TUV, SGS, BV, Lloyd's Register or a nominated agency.
- Marking and traceability. Heat number, grade and item number hard stamped or vibro etched per specification.
Applications for Nimonic 86 forgings
Alloy 86 is a high-temperature oxidation-resistant alloy, specified for hot and thermally cycled service. For ambient-temperature wet corrosion duty a Hastelloy or duplex grade is normally the correct selection.
| Sector | Typical forged components | Function of the alloy |
|---|---|---|
| Aero and industrial gas turbines | Combustion chamber components, afterburner parts, seal rings, forged and rolled rings | Withstanding repeated 1050 °C thermal cycles without scale spalling |
| Heat-treatment furnaces | Retort flanges, muffle supports, roller and fan shafts, fixture bars, hearth components | Continuous high-temperature service with frequent charge cycling |
| Power generation | Transition rings, forged discs, sleeves, hot gas path hardware | Creep strength combined with scaling resistance through start-stop cycles |
| Petrochemical and refining | Forged flanges, tube sheets, nozzle bodies, hangers, tube supports | High-temperature oxidation and carburising resistance |
| High-temperature valves | Valve bodies, seat rings, stems, blocks, bonnets | Dimensional stability and scale resistance in hot gas lines |
| Thermal processing and incineration | Support rings, rolled rings, grate and hanger components | Resistance to oxidation, scaling and thermal shock |
Related open-die forging capability at Jiangyin Jiangnan Metal covers forged round bars, forged crankshafts and the full range of open-die forged parts in carbon, alloy, tool and stainless grades as well as nickel-base superalloys.
Nimonic 86 compared with related high-temperature alloys
Orientation for cases where the specification is still open. Maximum temperatures below are indicative oxidation limits, not load-bearing limits.
| Alloy | Nominal chemistry | Strengthening | Indicative oxidation limit | Main advantage |
|---|---|---|---|---|
| Nimonic 86 | Ni-25Cr-10Mo-0.03Ce | Solid solution | approx. 1050 °C | Cyclic oxidation and scaling resistance, weldability |
| Nimonic 75 | Ni-20Cr-Ti | Solid solution | approx. 950 to 1000 °C | Lower cost for less demanding hot service |
| Nimonic 80A | Ni-20Cr-Ti-Al | Precipitation hardened | approx. 815 °C | Higher strength at moderate temperature, engine valves |
| Nimonic 90 | Ni-20Cr-18Co-Ti-Al | Precipitation hardened | approx. 920 °C | Turbine blades and discs, high stress-rupture strength |
| Nimonic 263 | Ni-20Cr-20Co-6Mo-Ti-Al | Precipitation hardened | approx. 850 °C | Formability in the annealed state plus aged strength |
| Haynes 230 | Ni-22Cr-14W-2Mo-La | Solid solution and carbide | approx. 1100 °C | Long-term high-temperature strength and thermal stability |
| Inconel 617 | Ni-22Cr-12Co-9Mo-Al | Solid solution | approx. 1100 °C | Creep strength in very high temperature structural duty |
Indicative comparison for orientation only. Confirm alloy selection against the project specification, the design code and creep-rupture data for the actual load and design life. Jiangyin Jiangnan Metal forges every grade listed above.
How to order Nimonic 86 forgings
The following seven items are needed to return a firm price rather than a budget range.
- Drawing or dimensions. A PDF or DWG drawing is preferred. Rough dimensions with the required machining allowance are sufficient for a budget price.
- Quantity. Prototype single pieces and repeat production batches are both accepted.
- Delivery condition. As forged, solution annealed, rough machined or finish machined.
- Specification. The applicable material or project standard, and any customer requirement that overrides it.
- Certificate level. EN 10204 3.1, or 3.2 with a named third-party inspection agency.
- NDT requirement. Ultrasonic standard and acceptance class (EN 10228-3, SEP 1921 or ASTM A388), plus dye penetrant if required.
- Destination. Port or delivery address, and the incoterm.
Nimonic 86 frequently asked questions
Common technical and commercial questions about Alloy 86 and its supply as forgings.
What is Nimonic 86?
Nimonic 86, also written Nimonic alloy 86 or Alloy 86, is a nickel-chromium-molybdenum superalloy containing nominally 25% chromium, 10% molybdenum and a 0.03% cerium addition, with nickel as the balance. It is a solid-solution alloy developed for high creep strength and cyclic oxidation resistance at 1050 °C (1920 °F). It is used for gas turbine combustion chambers, afterburner parts and heat-treatment furnace equipment.
What is the chemical composition of Nimonic 86?
The nominal composition of Nimonic 86 is 0.05% carbon, 25.0% chromium, 10.0% molybdenum, 0.015% magnesium, 0.03% cerium, with nickel as the balance at approximately 65%. The cerium is a reactive rare-earth addition that improves adhesion of the protective chromium oxide scale during thermal cycling.
What is the maximum service temperature of Nimonic 86?
Nimonic 86 is rated for cyclic and continuous service to approximately 1050 °C (1920 °F), which is the temperature at which its oxidation and scaling resistance was characterised. Load-bearing capability falls away well below that figure. The 0.2% proof stress drops from about 251 MPa at 300 °C to about 44 MPa at 1050 °C, so the practical limit for a stressed forging is normally set from creep data for the actual load and design life.
Can Nimonic 86 be age hardened or precipitation hardened?
No. Nimonic 86 is solid-solution strengthened and cannot be age hardened, unlike Nimonic 80A, Nimonic 90 or Nimonic 263. Its strength comes from chromium and molybdenum in solution rather than from a gamma-prime precipitate. Several supplier datasheets list a solution treatment followed by an ageing cycle for Alloy 86, which is incorrect. The correct treatment is a single solution anneal. Prolonged exposure between 500 and 600 °C can cause carbide precipitation followed by recrystallisation, so long holds in that range should be avoided.
What heat treatment is used for Nimonic 86 forgings?
Nimonic 86 bar and forgings are solution annealed for 2 to 4 hours at 1150 °C, then air cooled. Sheet is annealed for 5 to 15 minutes at 1150 °C and air cooled. Jiangyin Jiangnan Metal Co., Ltd. heat treats Nimonic 86 forgings to this cycle as standard and works to a customer-specified cycle where a project specification requires it, with the furnace chart supplied against the material certificate.
Is Nimonic 86 weldable?
Yes. Nimonic 86 has good weldability. Joints made by the tungsten inert gas process using matching-composition filler wire develop properties comparable to the base material. As with all nickel-base alloys the joint area must be cleaned of oil, grease, marking crayon, paint and shop dirt before welding, since these are sources of sulphur and lead embrittlement.
What is the difference between Nimonic 86 and Nimonic 75?
Both are solid-solution nickel-chromium alloys. Nimonic 86 carries 25% chromium plus 10% molybdenum and a cerium addition, while Nimonic 75 carries about 20% chromium with a small titanium addition and no molybdenum. In comparative cyclic oxidation testing at 1050 °C, Nimonic 86 recorded a lower spalling rate and a longer time to oxide breakaway than Nimonic 75, and it has higher creep strength. Nimonic 75 remains the lower-cost option for less demanding or less thermally cyclic duty.
Who manufactures Nimonic 86 forged rings and flanges?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China that forges Nimonic 86 to customer drawing. Product forms include seamless rolled rings, forged rings, flanges, shafts, discs and blanks, sleeves, bushings, tube sheets and round bars. Enquiries go to sales@steelforgepieces.com or +86 189 2135 9659.
What certificates are supplied with Nimonic 86 forgings?
Jiangyin Jiangnan Metal supplies Nimonic 86 forgings with an EN 10204 3.1 material certificate as standard, and EN 10204 3.2 with third-party endorsement by TUV, SGS, BV, Lloyd's Register or a nominated inspection agency on request. The package covers chemical analysis, mechanical test results, heat treatment record, dimensional report and the ultrasonic test report to EN 10228-3, SEP 1921 or ASTM A388.
What is the minimum order quantity for Nimonic 86 forgings?
There is no fixed piece-count minimum. Nimonic 86 forgings are made to order from a drawing, so a single prototype ring or a repeat production batch are both accepted. The practical minimum is set by the mill minimum melt or billet quantity for the grade. Send the drawing, the specification and the quantity and Jiangyin Jiangnan Metal will confirm achievable size, weight and lead time.
What information is needed to quote a Nimonic 86 forging?
Supply the drawing or the rough dimensions with machining allowance, the quantity, the delivery condition, the applicable specification, the required certificate level (EN 10204 3.1 or 3.2), any NDT requirement with acceptance class, and the destination port. Jiangyin Jiangnan Metal quotes against that package, normally within one to two working days.
About the manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. Production covers forged rings, seamless rolled rings, flanges, shafts, discs, sleeves, bushings, tube sheets and round bars, made to customer drawing in carbon steel, alloy steel, tool steel, stainless steel and nickel-base superalloys, including the Nimonic, Inconel, Incoloy, Hastelloy, Haynes, Monel and Udimet ranges.
Every forging is despatched with its own document pack: chemical analysis, mechanical test results, heat treatment records, dimensional report, ultrasonic test report and an EN 10204 3.1 or 3.2 material certificate.
- CompanyJiangyin Jiangnan Metal Co., Ltd.
- Factory addressNo.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone, WhatsApp, WeChat+86 189 2135 9659
- Emailsales@steelforgepieces.com
- Websitewww.steelforgepieces.com
- CapabilityOpen-die forgings, seamless rolled rings, forged flanges and bars