Jiangyin Jiangnan Metal
Seamless forged rings
Upset, punched, then expanded over a mandrel on the open-die press. Grain flow follows the circumference, so a seamless forged ring holds up better under hoop stress than a ring cut from plate.
Nickel-chromium-cobalt superalloy · Open-die forgings
Alloy 90 Forgings
Nimonic 90 / UNS N07090 / W.Nr. 2.4632 / NiCr20Co18Ti
Grade summary
Reviewed 14 Aug 2026 · Jiangyin Jiangnan Metal Co., Ltd.
Alloy 90 (Nimonic 90, UNS N07090) is a wrought, age-hardenable nickel-chromium-cobalt superalloy strengthened by titanium and aluminium additions, with creep-rupture strength and oxidation resistance up to 920 °C (1688 °F). It contains 18 to 21 % chromium and 15 to 21 % cobalt with nickel as balance, and is specified for turbine blades and discs, ring sections, hot-working tools, high-temperature springs and automotive exhaust valves.
Jiangyin Jiangnan Metal Co., Ltd., an integrated open-die forging factory in Jiangyin, Jiangsu Province, China, produces Alloy 90 as forged rings, discs, shafts, flanges, sleeves, bushings, tube sheets, round bars and forged pipes. The grade is vacuum induction melted in the plant's own 3 t VIM furnace and remelted by protective-atmosphere ESR (3 t or 6 t) or VAR (6 t), forged on 2,000 to 6,300 t open-die presses, heat treated to ASTM B637 and AMS 5829, ultrasonically tested to EN 10228-3, and certified to EN 10204 3.1 or 3.2. Finished pieces run from 1 kg to 5,000 kg, minimum order 1 kg or 1 piece, lead time 20 to 60 days.
- UNS
- N07090
- Werkstoff
- 2.4632 / 2.4969
- DIN
- NiCr20Co18Ti
- AMS
- 5829
- ASTM
- B637
- BS
- HR2 / 3075 NA19
- AFNOR
- NCK 20TA
- MSRR
- 7137 / 7017
Alloy 90 product forms we forge
Summary
Jiangyin Jiangnan Metal Co., Ltd. produces Alloy 90 (Nimonic 90 / UNS N07090) in ten open-die forged product forms: seamless forged rings, forged discs, forged shafts, forged flanges, forged sleeves and bushings, forged tube sheets, forged round bars, forged pipes and tubes, forged blocks and blanks, and custom near-net shapes forged to drawing. All are forged in-house on 2,000 to 6,300 tonne open-die presses from the plant's own VIM plus ESR or VIM plus VAR remelted stock.
Forged discs and blanks
Upset and drawn discs for turbine wheels, valve seats and gear blanks. Supplied as-forged, rough machined or finish machined to drawing.
Forged shafts and spindles
Stepped, eccentric and straight shafts, cogged on the open-die press with the finishing pass at the low end of the hot working range to control grain size.
Forged flanges
Weld-neck, slip-on, blind and custom-drilled flanges for pressure vessels, air receivers and shell-and-tube heat exchangers.
Sleeves and bushings
Hollow forged sections for subsea and deepwater production systems, industrial air compressors, power generators and nitrogen generators.
Tube sheets
Thick forged plates for heat exchangers and process modules, supplied undrilled or drilled to the tube layout drawing.
Round bars and billets
Forged and peeled bar for downstream machining, fastener production and high-temperature springs.
Forged pipes and tubes
Bored and expanded hollow forgings for columns, towers, tanks, silos and preheaters where seamless tube is not available in this grade.
Valve components
Valve stems, seat rings, blocks and bodies for ball, check, globe, gate and plug valves and strainers.
Custom near-net shapes
Nozzles, manifolds, crankshafts, forged wheels, eccentric shafts and rolls forged to a customer drawing, with machining allowance agreed in advance.
The same forms are available in Nimonic 80A, Waspaloy, Inconel 625, 706 and X-750, Incoloy 800H and 825, Hastelloy C-276 and X, Monel 400 and K-500, and Rene 41. See related grades.
Chemical composition of Alloy 90
Summary
Alloy 90 (UNS N07090) contains nickel as balance, chromium 18.0 to 21.0 %, cobalt 15.0 to 21.0 %, titanium 2.0 to 3.0 % and aluminium 1.0 to 2.0 % by weight, with carbon limited to 0.13 % max, iron 1.5 % max, manganese 1.0 % max, silicon 1.0 % max and copper 0.2 % max. The titanium and aluminium together form the gamma-prime precipitate that gives the alloy its high-temperature strength.
| Element | Symbol | Min % | Max % | Role in the alloy |
|---|---|---|---|---|
| Nickel | Ni | Balance | – | Austenitic matrix |
| Chromium | Cr | 18.0 | 21.0 | Oxidation and hot-corrosion resistance |
| Cobalt | Co | 15.0 | 21.0 | Solid-solution strengthening, raises the solvus |
| Titanium | Ti | 2.0 | 3.0 | Gamma-prime former, Ni3(Al,Ti) |
| Aluminium | Al | 1.0 | 2.0 | Gamma-prime former, oxidation resistance |
| Iron | Fe | – | 1.5 | Residual |
| Manganese | Mn | – | 1.0 | Residual, deoxidiser |
| Silicon | Si | – | 1.0 | Residual, deoxidiser |
| Copper | Cu | – | 0.2 | Residual |
| Zirconium | Zr | – | 0.15 | Grain-boundary strengthening |
| Carbon | C | – | 0.13 | Carbide formation |
| Boron | B | – | 0.02 | Grain-boundary strengthening, creep life |
| Sulphur | S | – | 0.015 | Impurity limit |
| Lead | Pb | – | 0.0020 | Impurity limit, embrittlement |
Composition per BS HR2 and AMS 5829. Where a customer specification differs, the customer specification governs. State it on the enquiry and it will be reflected on the mill certificate.
Mechanical properties of Alloy 90
Summary
In the fully heat-treated condition, Alloy 90 forged and extruded bar meets minimum room-temperature values of 695 MPa 0.2 % proof strength, 1080 MPa tensile strength, 20 % elongation and 310 HV hardness. Typical hardness after the full solution and age cycle falls in the 250 to 350 HV band.
| Condition | Test temp. | 0.2 % proof (MPa) | Tensile (MPa) | Elongation (%) | Hardness (HV) |
|---|---|---|---|---|---|
| Solution + aged bar | Room temp. | 695 min | 1080 min | 20 min | 310 min |
These are specification minima for forged and extruded bar, not design allowables. Section size, forging reduction and grain size all affect achieved properties. On heavy sections, agree the test location and orientation (T/2, T/4, longitudinal or tangential) on the order. Elevated-temperature tensile, stress-rupture and impact testing can be added on request.
Physical properties of Alloy 90
| Property | Value | Condition |
|---|---|---|
| Density | 8.18 g/cm3 | 20 °C |
| Melting range | 1310 to 1370 °C | 2390 to 2500 °F |
| Modulus of elasticity | 220 GPa | 20 °C |
| Modulus of elasticity | 185 GPa | 538 °C |
| Modulus of rigidity | 82 GPa | 20 °C |
| Mean coeff. of expansion | 14.8 um/m·°C | 20 to 538 °C |
| Electrical resistivity | 118 uohm·cm | 20 °C |
| Max. strength service temp. | about 704 °C (1300 °F) | High-strength duty |
| Max. creep / oxidation temp. | about 920 °C (1688 °F) | Creep-resisting duty |
| Magnetic response | Non-magnetic | Fully austenitic |
Typical published values for the grade, for reference only, not for design calculation. Confirm design data against the governing specification and your own qualification testing.
Heat treatment of Alloy 90 forgings
Summary
The standard heat treatment for Alloy 90 forgings is a solution treatment of 8 hours at 1080 °C (1975 °F) followed by air cooling, then a precipitation age of 16 hours at 700 °C (1290 °F) followed by air cooling. Forgings are supplied in the fully heat-treated condition at 250 to 350 HV, and machining should follow this cycle rather than precede it.
| Stage | Temperature | Soak | Cooling | Purpose |
|---|---|---|---|---|
| Solution | 1080 °C / 1975 °F | 8 h | Air cool | Dissolve gamma prime, homogenise the matrix |
| Precipitation age | 700 °C / 1290 °F | 16 h | Air cool | Precipitate fine Ni3(Al,Ti) for creep strength |
Furnace charts, thermocouple positions and a heat-treatment certificate can be supplied with each lot. Where the customer specification calls for a different cycle, such as a lower ageing temperature for spring stock or a double age, state it on the enquiry and the forgings will be processed and certified to that cycle instead.
Specifications and equivalent designations
Summary
Alloy 90 is designated UNS N07090 and Werkstoff Nr. 2.4632, also 2.4969. Equivalent designations include DIN NiCr20Co18Ti, AFNOR NCK 20TA, AMS 5829, ASTM B637, BS HR2, HR202, HR402 and HR501 to HR503, BS 3075 NA19, MSRR 7137 and MSRR 7017. Nimonic 90 is the Special Metals Corporation trade name for this grade, and Udimet 90 is an equivalent trade name.
| System / region | Designation | Applies to |
|---|---|---|
| UNS (USA) | N07090 | All product forms |
| Werkstoff (Germany) | 2.4632 / 2.4969 | All product forms |
| DIN (Germany) | NiCr20Co18Ti | All product forms |
| AFNOR (France) | NCK 20TA | All product forms |
| SAE AMS | AMS 5829 | Bar, wire, forging stock |
| ASTM | ASTM B637 | Precipitation-hardening bar and forgings, high-temperature service |
| BS (UK) | HR2, HR501, HR502, HR503 | Rod, bar, wire, forging stock |
| BS (UK) | HR202 | Plate, sheet, strip |
| BS (UK) | HR402 | Pipe and tube |
| BS (UK) | BS 3075 NA19 | Wire |
| MSRR (Rolls-Royce) | MSRR 7137, MSRR 7017 | Aero-engine material |
| AECMA (aerospace EU) | prEN 2295 to 2299 | Bar, sheet, tube |
| Trade names | Nimonic 90, Udimet 90 | Proprietary designations |
NIMONIC and UDIMET are registered trademarks of their respective owners and are used here only to identify the alloy grade. Jiangyin Jiangnan Metal Co., Ltd. is an independent forging manufacturer and is not affiliated with, endorsed by or licensed by those trademark holders.
How Alloy 90 forgings are produced
Melting, forging, heat treatment, machining and testing all happen inside the same factory, so a single heat number follows the part from the VIM furnace to the packing case. Each of the nine stages below generates a record that ends up in the certification package.
- Primary melt, 3 t VIMAlloy 90 is vacuum induction melted. A vacuum melt is not optional for this grade: the 2 to 3 % titanium and 1 to 2 % aluminium that form the gamma-prime precipitate oxidise away in an air melt, and the resulting oxide film gets forged into the part as stringers. Heat number and full ladle analysis are recorded here.
- Remelt, ESR or VARThe VIM electrode is remelted in a 3 t or 6 t protective-atmosphere electroslag furnace, or in the 6 t vacuum arc furnace, to refine the solidification structure, cut macro-segregation and lower inclusion content. Triple melt using VIM, ESR and VAR is available for critical rotating parts.
- Ingot conditioningSurface grinding and inspection of the remelt ingot before the first heat, so surface defects are not forged into the part.
- Open-die forgingHot working between 1050 and 1200 °C on 2,000 t, 4,000 t or 6,300 t presses, with 750 kg to 5 t hammers for smaller sections. Cogging, upsetting, punching and mandrel expansion as the geometry requires, with reheats between passes and the finishing reduction taken at the low end of the range to control grain size.
- Solution treatment and ageing8 hours at 1080 °C in a 1200 °C-class car-bottom furnace, air cool, then 16 hours at 700 °C, air cool. All furnaces are chart-recorded with calibrated thermocouples.
- Rough machiningTurning, boring and facing on vertical lathes up to 5,000 mm diameter and CNC lathes to 10,000 mm between centres, removing scaled surfaces and preparing a clean face for ultrasonic inspection.
- Non-destructive testingUltrasonic testing to EN 10228-3, SEP 1921 or ASTM A388 on one of three UT sets, plus magnetic particle inspection where the grade and geometry allow.
- Mechanical, chemical and metallographic testingTensile to 600 kN, Charpy impact with a low-temperature bath to minus 60 °C, hardness, spectrometric analysis and metallography, all in the plant's own laboratory, on the sacrificial test prolongation at the location and orientation agreed on the order.
- Certification, marking and packingEN 10204 3.1 mill certificate or 3.2 third-party witnessed certificate, hard stamping or vibro-etch marking with heat number, then export packing in fumigated cases or on steel pallets.
Factory equipment list
Summary
Jiangyin Jiangnan Metal Co., Ltd. runs its own melting, forging, heat treatment, machining and testing departments. Melting capacity covers 2, 8 and 25 t induction furnaces, a 25 t electric furnace with 25 t and 50 t ladle furnaces and 30 t and 60 t VOD units, plus a 3 t VIM furnace, 3 t and 6 t protective-atmosphere ESR furnaces and a 6 t VAR furnace for superalloys. Forging is on 6,300 t, 4,000 t and 2,000 t open-die presses with 750 kg to 5 t hammers.
Melting and forging
| Process | Equipment | Qty | Used for |
|---|---|---|---|
| Smelting | 2 t, 8 t, 25 t induction furnace (IF) | 3 | Carbon and alloy steel |
| Smelting | 25 t EF, 25 t LF, 50 t LF, 30 t VOD, 60 t VOD | 5 | Alloy and stainless steel, degassing and decarburisation |
| Special melting | 3 t vacuum induction furnace (VIM) | 1 | Alloy 90 primary melt, protects Ti and Al |
| Special melting | 3 t and 6 t protective-atmosphere electroslag furnace (ESR) | 2 | Alloy 90 remelt, structure refinement |
| Special melting | 6 t vacuum arc remelting furnace (VAR) | 1 | Alloy 90 remelt, lowest inclusion route |
| Forging | 6,300 t open-die hydraulic press | 1 | Heavy sections, large rings and discs |
| Forging | 4,000 t open-die hydraulic press | 1 | Mid-range forgings |
| Forging | 2,000 t open-die hydraulic press | 1 | Smaller forgings, close control |
| Forging | 5 t, 3 t, 2 t, 1 t and 750 kg hammers | 5 | Bars, small shafts, blanks |
Alloy 90 is melted on the VIM plus ESR or VIM plus VAR route. The EF, LF and VOD line handles carbon, alloy and stainless steel grades, not gamma-prime strengthened superalloys.
Heat treatment
| Model | Type | Working zone (m) | Temp. class | Qty |
|---|---|---|---|---|
| RTX-12-350KW | Car-bottom | 3.5 x 1.3 x 1.1 | 1200 °C | 3 |
| RTX-9-900KW | Car-bottom | 6.0 x 3.5 x 2.3 | 950 °C | 1 |
| RTX-9-810KW | Car-bottom | 8.0 x 2.0 x 2.0 | 950 °C | 2 |
| RTX-9-720 | Car-bottom | 5.5 x 3.0 x 1.8 | 950 °C | 2 |
| RTX-9-530KW | Car-bottom | 8.0 x 1.5 x 1.2 | 950 °C | 2 |
| RTX-9-430 | Car-bottom | 6.5 x 1.5 x 1.1 | 950 °C | 1 |
| RTX-9-430 | Car-bottom | 5.5 x 1.5 x 1.1 | 950 °C | 1 |
| RJ-9-850KW | Well / pit type | 15.0 long x 1.5 dia. | 950 °C | 2 |
Note on furnace size
Alloy 90 is solution treated at 1080 °C, above the 950 °C class of most of the furnace line. The solution stage therefore runs in the 1200 °C-class RTX-12 car-bottom furnaces, and their 3,500 x 1,300 x 1,100 mm working zone, not the press, sets the dimensional limit on a single Alloy 90 forging: roughly 1,250 mm diameter for a ring or disc lying flat, or 3,400 mm for a shaft. Weight is unaffected, since 5,000 kg fits inside that zone. The 700 °C ageing stage can use any furnace in the line, up to the 6.0 x 3.5 x 2.3 m car-bottom furnace or the 15 m pit furnaces.
Machining
| Type | Capacity | Qty |
|---|---|---|
| Vertical lathe | 5,000 mm dia. | 1 |
| Vertical lathe | 3,500 mm dia. | 1 |
| Vertical lathe | 2,500 mm dia. | 4 |
| Horizontal lathe | 1,800 mm dia. x 8 m | 3 |
| Horizontal lathe | 1,400 mm dia. x 8 m | 2 |
| Horizontal lathe | 1,600 mm dia. x 14 m / 1,250 mm dia. x 10 m | 1 |
| CNC lathe | 2,000 mm dia. x 10,000 mm | 1 |
| CNC lathe | 2,000 mm dia. x 8,000 mm | 1 |
| CNC lathe | 1,600 mm dia. x 3,300 mm | 3 |
| Deep-hole drilling machine | 1,600 mm dia. x 10,000 mm | 1 |
Laboratory and non-destructive testing
| Category | Instrument | Model |
|---|---|---|
| Chemical analysis | Mobile optical emission spectrometer | SPECTROTEST TXC25 |
| Chemical analysis | Infrared carbon and sulphur analyser | HIR-9440D |
| Chemical analysis | Handheld alloy composition analyser (XRF) | X-Mwt3000TX |
| Chemical analysis | High-speed digital automatic analyser | HC-II |
| Chemical analysis | Analytical balance | TG328A |
| Mechanical | 600 kN hydraulic universal testing machine | WE-600B |
| Mechanical | 300 kN computer-controlled universal testing machine | WDW-300 |
| Mechanical | Pendulum impact testing machine | JBN-300 |
| Mechanical | Low-temperature bath for impact test, to minus 60 °C | DWC-60 |
| Mechanical | Charpy specimen projector | CST-50 |
| Mechanical | Impact specimen notch broaching machine | VU-2D |
| Hardness | Leeb hardness tester, convertible to HV, HB, HRC | TH140 |
| Metallography | Metallurgical microscope | XJP-6A |
| Metallography | Specimen mounting press, pre-grinder, polisher | XQ-2B / M-2 / P-2 |
| NDT | Full-digital intelligent ultrasonic flaw detector | PXUT-3300 |
| NDT | Digital ultrasonic flaw detector | USM35XS |
| NDT | Ultrasonic flaw detector | CTS-22 |
| NDT | Multipurpose magnetic particle crack detector | CYE-3A |
| NDT | Industrial electronic endoscope | DNJ |
| Specimen prep | CNC wire-cut EDM | DK7720 |
| Specimen prep | Horizontal-spindle surface grinder | MYS7120 |
| Specimen prep | Sealed sample preparation grinder, drying oven | GJ-I / 101-2A |
Chemical analysis, tensile, impact, hardness, metallography, ultrasonic and magnetic particle inspection are all done in-house, so test results do not wait on an outside laboratory. Radiographic testing is subcontracted when a specification calls for it.
Size and weight capability
Summary
Alloy 90 forgings are supplied from 1 kg to 5,000 kg finished weight. What limits a part is its dimensions rather than its mass: the 1080 °C solution stage must run in a 1200 °C-class furnace whose 3,500 x 1,300 x 1,100 mm working zone caps ring and disc diameter at roughly 1,250 mm and shaft length at roughly 3,400 mm. A 5,000 kg solid disc of 1,200 mm diameter by 540 mm thick fits inside that zone.
Alloy 90 practical limits
| Parameter | Limit | Set by |
|---|---|---|
| Finished piece weight | 1 kg to 5,000 kg | Remelt ingot supply |
| Solution-treat envelope | 3,500 x 1,300 x 1,100 mm | 1200 °C-class furnace working zone, 1080 °C stage |
| Ring / disc outside diameter | up to about 1,250 mm | Solution furnace width, not the press |
| Shaft / bar length | up to about 3,400 mm | Solution furnace length |
| Section height / thickness | up to about 1,000 mm | Solution furnace height |
| Ageing envelope | up to 6,000 x 3,500 x 2,300 mm | 950 °C-class furnace line, 700 °C stage |
| In-house remelt ingot | 6 t max | 6 t ESR / 6 t VAR furnace |
Forging and machining reach well past this. The 6,300 t press and the 5,000 mm vertical lathe handle far larger parts, and it is the 1080 °C solution stage that sets the in-house limit. Parts outside the furnace zone are still quoted, with the solution treatment subcontracted and shown on the quotation.
Factory envelope, all grades
For carbon, alloy, tool and stainless steel grades, melted on the EF, LF and VOD line and heat treated below 950 °C, the envelope is considerably larger.
| Operation | Maximum |
|---|---|
| Melt size | 60 t (VOD) |
| Press capacity | 6,300 t |
| Heat treatment, car-bottom | 8.0 x 2.0 x 2.0 m and 6.0 x 3.5 x 2.3 m |
| Heat treatment, pit furnace | 15 m long x 1.5 m dia. |
| Vertical turning | 5,000 mm dia. |
| Horizontal turning | 1,800 mm dia. x 8 m; 1,600 mm dia. x 14 m |
| CNC turning | 2,000 mm dia. x 10,000 mm |
| Deep-hole drilling | 1,600 mm dia. x 10,000 mm |
Commercial terms
| Item | Detail |
|---|---|
| Minimum order | 1 kg or 1 piece, single prototypes and one-off replacement parts accepted |
| Lead time | 20 to 60 days from order confirmation, depending on size, melting route and machining scope |
| Melting route | VIM plus ESR or VIM plus VAR as standard, triple melt on request |
| Supply condition | As-forged and heat treated, rough machined, or finish machined to drawing |
| Certification | EN 10204 3.1 as standard, EN 10204 3.2 with TUV, SGS, BV or Lloyd's Register on request |
| Incoterms | EXW, FOB Shanghai or Ningbo, CIF or DDP |
Testing, inspection and certification
Summary
Alloy 90 forgings from Jiangyin Jiangnan Metal are ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 on the plant's own UT equipment, and supplied with an EN 10204 3.1 mill certificate as standard or an EN 10204 3.2 certificate witnessed by a third-party inspection body such as TUV, SGS, Bureau Veritas or Lloyd's Register. Chemical analysis, tensile, impact, hardness and metallographic testing all happen in the factory's own laboratory.
| Test | Standard | Included |
|---|---|---|
| Ladle and product chemical analysis | OES / infrared combustion | In-house, standard |
| Ultrasonic testing | EN 10228-3 / SEP 1921 / ASTM A388 | In-house, standard, class per order |
| Tensile test | ASTM E8 / ISO 6892-1 | In-house, standard, to 600 kN |
| Hardness test | ASTM A956 Leeb, converted to HV or HB | In-house, standard |
| Dimensional inspection | Per drawing | In-house, standard |
| Charpy impact, ambient to minus 60 °C | ASTM E23 / ISO 148-1 | In-house, on request |
| Metallography and grain size | ASTM E112 | In-house, on request |
| Magnetic particle inspection | ASTM E709 | In-house, on request |
| Liquid penetrant inspection | ASTM E165 | On request |
| Elevated-temperature tensile | ASTM E21 | Subcontracted, on request |
| Stress-rupture and creep | ASTM E139 | Subcontracted, on request |
| Radiographic testing | ASTM E94 | Subcontracted, on request |
| Third-party witness | EN 10204 3.2 | TUV, SGS, BV, Lloyd's, on request |
Each forging is marked with the heat number, grade, drawing or item number and lot, so the part stays traceable to its certificate after it leaves the factory. Test reports are issued in English, and a scanned copy can be emailed for approval before shipment.
Applications for Alloy 90 forgings
Summary
Alloy 90 forgings are used where a component has to carry load above 700 °C: gas turbine blades, discs and ring sections, hot-working tools and die-casting inserts, high-temperature springs and fasteners, automotive exhaust valves, furnace and heat-treatment equipment components, boiler tube supports, and valve internals in oil and gas service.
| Industry | Typical components | Why Alloy 90 |
|---|---|---|
| Power generation and gas turbine | Turbine blades, discs, ring sections, spindles, gears, gearbox shafts, gas-compressor rotors | Creep-rupture strength and oxidation resistance to 920 °C |
| Oil, gas and offshore | Forged discs, sleeves, bushings, wellhead and Christmas-tree parts, subsea and deepwater production hardware | Strength retention plus resistance to hot corrosive environments |
| Valves and flow control | Valve stems, seat rings, blocks, bodies for ball, check, globe, gate and plug valves and strainers | Galling resistance and hot strength in steam and process service |
| Pressure equipment | Forged flanges, tube sheets, forged pipes and tubes for pressure vessels, air receivers, shell-and-tube heat exchangers | High allowable stress at elevated temperature |
| Process plant | Columns, towers, tanks, silos, process modules, preheaters, crystalliser parts, forged nozzles, manifolds | Oxidation resistance in continuous hot service |
| Automotive and heavy engine | Exhaust valves, eccentric shafts, crankshafts, turbocharger components | Fatigue strength at exhaust-gas temperature |
| Tooling and heat treatment | Hot-working tools, die-casting inserts and cores, forged rolls, forged wheels, furnace components, boiler tube supports | Hot hardness and thermal-fatigue resistance |
| Springs and fasteners | High-temperature springs, studs, bolts and retaining hardware | Relaxation resistance to about 600 °C |
Machining, welding and hot working guidance
Machining Alloy 90
Alloy 90 should be in the fully heat-treated condition for all machining operations. The material hardness in this condition, 250 to 350 HV, calls for stringent technique: rigid setups with minimum tool overhang, positive-rake carbide or ceramic tooling, reduced surface speed with a heavy positive feed, and flood coolant directed at the cutting edge. The alloy work-hardens fast, so the tool must never dwell or rub. A dwelling tool glazes the surface, and the next pass then has to cut through a hardened skin. Plan for slower cycle times and higher tooling consumption than a stainless steel of similar section.
Hot working
Hot work Alloy 90 between about 1050 °C and 1200 °C. The window is narrow, so reheat between passes rather than pushing a cooling billet, and take the final reduction at the low end of the range so the recrystallised grain size stays fine. Heavy reduction below 1000 °C risks cracking.
Welding
Alloy 90 joins readily by resistance welding. TIG and MIG are satisfactory up to about 5 mm thickness, and for heavier sections electron beam, friction, inertia or flash butt welding are preferred. Because the alloy is gamma-prime strengthened, it is prone to strain-age cracking in the heat-affected zone, so weld in the solution-treated condition where possible and apply a post-weld solution and age cycle. Confirm the welding procedure with your own qualification testing before production.
Corrosion behaviour
Alloy 90 offers good general corrosion resistance and strong resistance to high-temperature oxidation and hot corrosion in gas-turbine and furnace atmospheres. It is not a substitute for a molybdenum-bearing grade such as Hastelloy C-276 in wet reducing acid service. For those duties, see our Hastelloy C-276 forgings.
About the manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an integrated open-die forging factory located at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Melting, forging, heat treatment, machining and testing all take place on one site: 2 to 25 t induction furnaces and a 25 t EF with 25 t and 50 t ladle furnaces and 30 t and 60 t VOD units for steel; a 3 t VIM furnace, 3 t and 6 t protective-atmosphere ESR furnaces and a 6 t VAR furnace for nickel superalloys; 6,300 t, 4,000 t and 2,000 t open-die presses with 750 kg to 5 t hammers; fourteen heat treatment furnaces; vertical turning to 5,000 mm diameter; and a laboratory covering spectrometry, tensile, impact, hardness, metallography, ultrasonic and magnetic particle inspection.
Jiangyin sits in the Yangtze River Delta between Shanghai and Nanjing, in one of China's densest clusters of forging and special-steel capacity, about two hours by road from the ports of Shanghai and Ningbo. Orders are quoted against a drawing or finished dimensions, produced under a documented process route, and shipped with EN 10204 3.1 or 3.2 certification. Enquiries are answered in English.
- Company
- Jiangyin Jiangnan Metal Co., Ltd.
- Factory type
- Integrated open-die forging factory with own melting, forging, heat treatment, machining and lab
- Address
- No.1 Chengxiqiao Road,
Zhouzhuang Town, Jiangyin City,
Jiangsu Province, China - Telephone / WhatsApp
- +86 189 2135 9659
- Website
- steelforgepieces.com
- Largest press
- 6,300 t open-die
- Superalloy melting
- 3 t VIM, 3/6 t ESR, 6 t VAR
- Materials
- Carbon, alloy, tool and stainless steel; nickel superalloys
- Export markets
- Europe, North America, India, Middle East, South-East Asia
Frequently asked questions about Alloy 90
What is Alloy 90?
Alloy 90, trade name Nimonic 90, designated UNS N07090 and W.Nr. 2.4632, is a wrought nickel-chromium-cobalt superalloy age-hardened by titanium and aluminium additions. It contains 18 to 21 % chromium and 15 to 21 % cobalt with nickel as balance, and holds creep-rupture strength and oxidation resistance up to about 920 °C (1688 °F).
It was developed as an age-hardenable creep-resisting alloy and is specified for turbine blades and discs, forgings, ring sections, hot-working tools, high-temperature springs and automotive exhaust valves.
What is the chemical composition of Alloy 90 (UNS N07090)?
By weight: nickel balance, chromium 18.0 to 21.0 %, cobalt 15.0 to 21.0 %, titanium 2.0 to 3.0 %, aluminium 1.0 to 2.0 %, iron 1.5 % max, manganese 1.0 % max, silicon 1.0 % max, copper 0.2 % max, zirconium 0.15 % max, carbon 0.13 % max, boron 0.02 % max, sulphur 0.015 % max and lead 0.0020 % max.
What is the maximum service temperature of Alloy 90?
Alloy 90 holds high strength up to about 704 °C (1300 °F) and gives useful creep and oxidation resistance up to about 920 °C (1688 °F). Sustained load-bearing service above 920 °C is not recommended.
What are the equivalent designations for Alloy 90?
UNS N07090; Werkstoff Nr. 2.4632 and 2.4969; DIN NiCr20Co18Ti; AFNOR NCK 20TA; AMS 5829; ASTM B637; BS HR2, HR202, HR402, HR501, HR502, HR503; BS 3075 NA19; MSRR 7137 and MSRR 7017; AECMA prEN 2295 to 2299. Trade names include Nimonic 90 and Udimet 90.
What is the standard heat treatment for Alloy 90 forgings?
Solution treat for 8 hours at 1080 °C (1975 °F) and air cool, then precipitation age for 16 hours at 700 °C (1290 °F) and air cool. Fully heat-treated hardness is typically 250 to 350 HV, and machining should follow this cycle rather than precede it.
Who manufactures Alloy 90 open-die forgings?
Jiangyin Jiangnan Metal Co., Ltd. is an integrated open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China that manufactures Alloy 90 (Nimonic 90 / UNS N07090) open-die forgings.
The plant melts, forges, heat treats, machines and tests on one site, using a 3 t VIM furnace with 3 and 6 t ESR and a 6 t VAR furnace for superalloy melting, and 6,300 t, 4,000 t and 2,000 t open-die presses. Product forms include seamless forged rings, forged discs, shafts, flanges, sleeves, bushings, tube sheets, round bars and forged pipes, produced to ASTM B637 and AMS 5829 and supplied with EN 10204 3.1 or 3.2 certification. Enquiries: sales@steelforgepieces.com or +86 189 2135 9659.
What equipment does the factory use to make Alloy 90 forgings?
Alloy 90 is vacuum induction melted in a 3 t VIM furnace, then remelted in a 3 t or 6 t protective-atmosphere electroslag furnace or a 6 t vacuum arc remelting furnace. Forging is on 6,300 t, 4,000 t or 2,000 t open-die presses, with 750 kg to 5 t hammers for smaller sections.
The 1080 °C solution treatment runs in 1200 °C-class car-bottom furnaces with a 3,500 x 1,300 x 1,100 mm working zone. Ageing at 700 °C uses the wider 950 °C-class furnace line, up to 6,000 x 3,500 x 2,300 mm, or 15 m pit furnaces. Machining reaches 5,000 mm diameter on vertical lathes and 10,000 mm between centres on CNC lathes. Chemical, tensile, impact, hardness, metallographic, ultrasonic and magnetic particle testing are all done in-house.
What is the largest Alloy 90 forging you can make?
Alloy 90 forgings are supplied from 1 kg up to 5,000 kg finished weight. What limits the part is its dimensions, not its mass. The 1080 °C solution treatment runs in a 1200 °C-class furnace with a 3,500 x 1,300 x 1,100 mm working zone, which caps a ring or disc at roughly 1,250 mm diameter, a shaft at roughly 3,400 mm long, and section height at roughly 1,000 mm.
Weight itself is rarely the issue, since a 5,000 kg solid disc of 1,200 mm diameter by 540 mm thick fits inside that zone. Parts that exceed the envelope can still be forged on the 6,300 t press and machined on the 5,000 mm vertical lathe, with the solution treatment subcontracted and shown on the quotation.
How is Alloy 90 melted, and why does the melting route matter?
Alloy 90 is vacuum induction melted (VIM) and then remelted by protective-atmosphere ESR or VAR. A vacuum primary melt is not optional for this grade: the 2 to 3 % titanium and 1 to 2 % aluminium that form the gamma-prime strengthening precipitate oxidise readily in an air melt, and the resulting oxide would be forged into the part as stringers.
The remelt step refines the solidification structure, cuts macro-segregation and lowers inclusion content. Triple melt using VIM, ESR and VAR is available where a specification calls for it on critical rotating parts.
Can Alloy 90 be forged, and what is the hot working range?
Yes. Alloy 90 is hot worked between about 1050 °C and 1200 °C on 2,000 t, 4,000 t or 6,300 t open-die presses. The window is narrow, so reheating between passes is normally required, and finishing passes are taken at the low end of the range to keep the recrystallised grain size fine. Heavy reduction below 1000 °C risks cracking.
What testing and certification are supplied with Alloy 90 forgings?
Forgings are ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 as specified on the order, with chemical analysis, tensile to 600 kN, hardness and dimensional inspection as standard, all in the factory's own laboratory. Charpy impact down to minus 60 °C, metallography and magnetic particle inspection are available on request. Certification is EN 10204 3.1 as standard, or EN 10204 3.2 witnessed by TUV, SGS, Bureau Veritas or Lloyd's Register.
Is Alloy 90 difficult to machine?
It is harder to machine than stainless steel but entirely workable with the right method. Machine in the fully heat-treated condition at 250 to 350 HV, using rigid setups, positive-rake carbide or ceramic tooling, reduced surface speed with heavy positive feed, and flood coolant. The alloy work-hardens fast, so avoid dwelling or rubbing, because a glazed surface forces the next pass to cut through a hardened skin.
Is Alloy 90 the same as Inconel?
No. Alloy 90 (Nimonic 90) is a nickel-chromium-cobalt alloy containing 15 to 21 % cobalt, whereas Inconel grades such as 600, 625 and 718 are nickel-chromium or nickel-chromium-molybdenum alloys with little or no deliberate cobalt addition. Both Nimonic and Inconel are Special Metals Corporation trade names, but they denote different alloy families with different strengthening mechanisms and service envelopes.
What is the difference between Alloy 90 and Nimonic 80A?
Nimonic 80A is a nickel-chromium alloy hardened with titanium and aluminium but without a deliberate cobalt addition. Alloy 90 adds 15 to 21 % cobalt, which raises the gamma-prime solvus and improves creep-rupture strength at the top of the temperature range. For duties near 900 °C, Alloy 90 generally outperforms 80A. For exhaust valves and lower-temperature fasteners, Nimonic 80A is often the more economical choice.
What is the minimum order quantity and lead time for Alloy 90 forgings?
The minimum order is 1 kg or 1 piece. Single prototypes, trial pieces and one-off replacement parts are accepted, so an order does not have to be a production batch.
Lead time is 20 to 60 days from order confirmation. Where a part falls in that range depends on size, whether the melting route is VIM plus ESR or VIM plus VAR, and how much machining is included in the scope. A firm date is given with the quotation.
How do I request a quotation for Alloy 90 forgings?
Send a drawing in PDF, DWG or STEP format, or the finished dimensions, together with the quantity, the applicable specification and the required certification level, to sales@steelforgepieces.com or telephone +86 189 2135 9659. A quotation follows with price, lead time and the proposed process route.
Request a quotation for Alloy 90 forgings
Send a drawing or the finished dimensions and you will receive a price, a firm delivery date and the proposed process route. Quotations are prepared by Jiangyin Jiangnan Metal Co., Ltd. in English.
Finished pieces from 1 kg to 5,000 kg, minimum order 1 kg or 1 piece. A single prototype or a one-off replacement part is a normal order here, not an exception. Lead time runs 20 to 60 days from order confirmation.
Include in your enquiry:
- Drawing in PDF, DWG or STEP, or finished dimensions: OD, ID, height or length, wall
- Quantity, and whether this is a one-off, a prototype or a repeat order
- Governing specification: ASTM B637, AMS 5829, BS HR2 or your own house spec
- Supply condition: as-forged, rough machined, or finish machined
- NDT class and certification level, EN 10204 3.1 or 3.2
- Destination port and required Incoterm