Designations and equivalent grades
NiCr20TiAl was developed from Nimonic 75 by adding aluminium and titanium. The additions make the alloy age-hardenable. During ageing they precipitate as Ni₃(Al,Ti), the gamma prime phase, which is coherent with the nickel matrix and obstructs dislocation movement at high temperature.
The alloy has been produced under several national systems since the 1940s and carries a number of designations. They refer to the same material. Drawings and enquiries frequently use different names for it, so the cross-reference below is the list we work from.
| System | Designation | Applies to |
|---|---|---|
| DIN / EN, Germany | NiCr20TiAl, 2.4952, 2.4631 | DIN 17742, DIN 17752/17754, EN 10269, EN 10090, EN 10302 |
| UNS, USA | N07080 | ASTM B637 / ASME SB-637 |
| Trade name | Nimonic 80A, Alloy 80A | Bar, forging stock, rings, discs |
| BS, UK | HR1, HR201, HR401, HR601 | BS 3076 bar; sheet, tube and forging classes |
| AFNOR, France | NC 20TA | Bar and forgings |
| GB/T, China | GH4080A | Bar, forgings, fasteners |
| Aerospace and defence | MSRR 7011, AECMA PrEN 2188 to 2197 | Bar, forgings, fasteners |
Cross-references are given for identification only. The purchase order governs. State the specification, revision and acceptance class required and the material will be forged, tested and certified to that document.
Chemical composition
Composition limits follow DIN 17742. Each heat is supplied with the ladle analysis on the EN 10204 certificate. Product analysis is available on request.
| Element | Min | Max | Function |
|---|---|---|---|
| Nickel, Ni | Balance | Austenitic FCC matrix | |
| Chromium, Cr | 18.0 | 21.0 | Forms the protective Cr₂O₃ scale |
| Titanium, Ti | 1.8 | 2.7 | Gamma prime former, primary strengthener |
| Aluminium, Al | 1.0 | 1.8 | Gamma prime former, aids oxidation resistance |
| Iron, Fe | 3.0 | Residual from raw material | |
| Cobalt, Co | 2.0 | Held low for nuclear service | |
| Manganese, Mn | 1.0 | Deoxidiser | |
| Silicon, Si | 1.0 | Deoxidiser | |
| Carbon, C | 0.10 | Grain-boundary carbides | |
| Copper, Cu | 0.20 | Residual | |
| Zirconium, Zr | 0.15 | Grain-boundary strengthening | |
| Sulphur, S | 0.015 | Impurity, limited for hot ductility | |
| Boron, B | 0.008 | Improves creep-rupture life | |
| Lead, Pb | 0.0025 | Tramp element, tightly controlled |
Two limits matter when specifying. Cobalt is capped at 2.0 %, which is why NiCr20TiAl is still specified for nuclear tube supports: low cobalt means low activation under neutron flux. Lead is held below 0.0025 % because trace lead embrittles grain boundaries at forging temperature and can open the piece during upsetting.
Mechanical and physical properties
Values apply to the solution-treated and precipitation-hardened condition at room temperature. Section size affects results. Heavy forgings cool more slowly through the ageing range and generally test toward the lower end of the range.
| Property | Typical | Specified minimum | Test method |
|---|---|---|---|
| Tensile strength, Rm | 1250 MPa | 1000 MPa | ISO 6892-1 / ASTM E8 |
| Yield strength, Rp0.2 | 780 MPa | 620 MPa | ISO 6892-1 / ASTM E8 |
| Elongation, A | 30 % | 20 % | ISO 6892-1 |
| Reduction of area, Z | 35 % | 12 % | ISO 6892-1 |
| Hardness | 320 to 360 HV | 300 HV | ISO 6507 / ASTM E92 |
| Property | Value | Note |
|---|---|---|
| Density | 8.19 g/cm³ | 0.296 lb/in³ at 20 °C |
| Maximum service temperature | 815 °C | 1500 °F, load-bearing service |
| Hot-working range | 1050 to 1200 °C | Finish above 1000 °C |
| Structure | FCC gamma + gamma prime | Ni₃(Al,Ti) precipitate |
| Magnetic response | Non-magnetic | Austenitic matrix |
Effect of ageing on strength
Ageing at 700 °C precipitates gamma prime particles of roughly 15 to 25 nm. Dislocations have to cut or bypass them, and that resistance produces the yield strength near 780 MPa. Above about 850 °C the particles coarsen and dissolve and strength falls quickly. This, rather than oxidation, sets the 815 °C service limit.
Forging and heat treatment route
The hot-working window for NiCr20TiAl is narrow. The alloy stiffens as it cools and will tear rather than flow if the finishing temperature drops too far, so reheats are built into the forging sequence.
| Stage | Parameters | Purpose |
|---|---|---|
| 1. Melting | EAF + VOD + ESR | Low gas and inclusion content, electroslag remelt for forging stock |
| 2. Soaking | 1150 to 1180 °C | Full dissolution before the first blow, slow ramp to avoid thermal cracking |
| 3. Open-die forging | 1050 to 1200 °C | Upsetting, drawing and punching, reheat below 1000 °C |
| 4. Ring rolling | 1050 to 1150 °C | Seamless rolled rings, radial and axial reduction |
| 5. Solution treatment | 1080 °C, 8 h, air cool | Dissolve gamma prime and recrystallise the forged structure |
| 6. Precipitation ageing | 700 °C, 16 h, air cool | Precipitate Ni₃(Al,Ti), develops final strength |
| 7. Testing | UT, mechanical, chemistry | EN 10228-3, SEP 1921 or ASTM A388, tensile, hardness |
- Forging ratio. A minimum 3:1 total reduction is applied to rings and discs unless the drawing calls for more. This breaks down the cast structure and gives a cleaner grain for ultrasonic testing.
- Grain flow. Ring blanks are punched and rolled rather than machined from plate, so the flow lines follow the circumference. A rolled ring therefore performs better than a ring cut from plate under hoop stress.
- Furnace records. Solution and ageing cycles are chart recorded and the traces are issued with the material certificate.
Forms produced in NiCr20TiAl
All forms are produced to customer drawing. Send the dimensions and piece weight with the enquiry and we will confirm whether the part falls within press and ring mill capacity.
Rings and seamless rolled rings
Turbine casing rings, combustor rings, retaining rings and spacer rings, ring rolled to near-net shape with circumferential grain flow.
Discs and blanks
Turbine and compressor disc blanks, blind blanks and pancakes, upset from ESR stock with controlled reduction.
Shafts and spindles
Straight, stepped and eccentric shafts, spindles and valve stems drawn out under the press with reheats to hold temperature.
Flanges and tube sheets
Weld-neck, blind and special flanges, and tube sheets for shell-and-tube heat exchangers.
Sleeves, bushings and tubes
Bored and trepanned hollows, sleeves, bushings and forged pipe sections for pressure duty.
Round bars and forging stock
Forged round, square and flat bar for onward machining, valve stems and fastener stock.
Testing, inspection and certification
Each NiCr20TiAl order is supplied with a documentation package traceable to the heat number stamped on the piece.
Ultrasonic testing
Straight and angle beam to EN 10228-3, SEP 1921 or ASTM A388, at the quality class named on the order.
Dye penetrant
Liquid penetrant to ASTM E165 or EN 571-1 on machined surfaces. NiCr20TiAl is non-magnetic, so PT replaces magnetic particle testing.
Tensile, hardness, impact
Room and elevated-temperature tensile, Brinell and Vickers hardness, Charpy V-notch where specified, from integral or prolongation test rings.
Spectrographic analysis
Ladle and product analysis by optical emission and combustion methods, reported against the DIN 17742 limits.
Grain size and microstructure
ASTM E112 grain size and gamma prime morphology checks on request, with photomicrographs.
EN 10204 3.1 and 3.2
Works certificate 3.1, or 3.2 countersigned by TUV, SGS, BV, Lloyd's Register or DNV at your nomination.
Third-party witness inspection, positive material identification at loading and customer NDT procedures can be arranged. State these at enquiry stage so the routing card is written correctly.
Applications
The alloy is selected when a part has to carry load between 600 and 815 °C, resist oxidation and sulphidation from combustion gas, and stay dimensionally stable through thermal cycling.
| Industry | Components | Forms supplied |
|---|---|---|
| Gas and steam turbines | Turbine blades and blade roots, casing rings, discs, bolts, spacers | Rolled rings, discs, bars |
| Automotive and motorsport | Exhaust valves, valve spindles, turbocharger fasteners | Bars, valve stem blanks |
| Nuclear power | Boiler tube supports and core internals fasteners, selected for cobalt below 2 % | Bars, rings, forged sections |
| Oil, gas and petrochemical | Wellhead and Christmas tree parts, subsea components, valve bodies, seat rings, stems | Blocks, discs, bushings, sleeves |
| Pressure equipment | Heat exchanger tube sheets, flanges, nozzles, air receivers, columns and towers | Tube sheets, flanges, forged pipe |
| Power transmission | Gears, spindles, rolls, compressor components | Discs, shafts, gear blanks |
| Hot-work tooling | Forging hammer dies, swaging dies, shear blades, die-casting inserts and cores | Blocks, discs |
| Marine and heavy industry | Manifolds, wheels, rolls for pulp, paper and pharmaceutical plant | Rings, wheels, rolls |
Comparison with neighbouring alloys
NiCr20TiAl sits between the solid-solution nickel alloys and the higher-strength cobalt-bearing grades. The table covers the alloys it is most often compared against.
| Alloy | UNS | Max service | Selected when |
|---|---|---|---|
| Nimonic 75 | N06075 | 925 °C | Oxidation resistance and formability are required rather than high strength. It is not age-hardenable. |
| NiCr20TiAl, Nimonic 80A | N07080 | 815 °C | Age-hardened strength is needed to 815 °C with cobalt held below 2 %. The default for nuclear parts and exhaust valves. |
| Inconel X-750 | N07750 | 815 °C | Similar strength is needed with better relaxation resistance in springs and bolting. |
| Waspaloy | N07001 | 870 °C | Creep-rupture demand exceeds Alloy 80A and the cobalt content is acceptable. |
| Inconel 718 | N07718 | 650 °C | Service stays below 650 °C and ease of welding and machining is the priority. |
NiCr20TiAl and Nimonic 90
The difference is cobalt content. NiCr20TiAl caps cobalt at 2 %. Nimonic 90, UNS N07090 and Werkstoff 2.4632, contains roughly 15 to 21 % cobalt, which raises creep-rupture strength between 815 and 920 °C. Nimonic 90 is used for hotter turbine sections. NiCr20TiAl is used where cobalt activation is a concern, where the specification names it, or where service does not exceed 815 °C.
Machining and welding
Machining
NiCr20TiAl work hardens rapidly. Use positive rake carbide tooling, rigid setups, a heavy constant feed and flood coolant. Avoid dwelling, since a stalled tool glazes the surface and the following pass has to cut through a hardened layer. Rough machine in the solution-treated condition where the drawing allows and finish after ageing.
Welding
TIG and MIG are both suitable provided the material is solution treated before welding. Nimonic 90 is the usual filler. Re-solution treat and re-age after welding to restore gamma prime strengthening and relieve residual stress. Keep heat input and interpass temperature low to limit the heat-affected zone.
Hot working
Work between 1050 and 1200 °C and return the piece to the furnace before it falls below 1000 °C. The alloy stiffens sharply as it cools and will tear rather than flow.
Surface preparation
The chromium oxide scale formed in service is protective and tenacious. Pickle or grit blast before penetrant inspection so that indications are not masked by oxide.
Manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin City, Jiangsu Province, China. We forge rings, seamless rolled rings, discs, shafts, flanges, bars, sleeves, bushings and tube sheets to customer drawings in carbon steel, alloy steel, tool steel, stainless steel and nickel-based superalloys, including NiCr20TiAl (Alloy 80A / UNS N07080 / W.Nr. 2.4952).
EAF + VOD + ESR
Forging stock is melted by electric arc furnace with vacuum oxygen decarburisation and electroslag remelting, which gives the low gas and inclusion content that heavy-section nickel forgings require.
Open-die forging and ring rolling
Upsetting, drawing, punching and ring rolling between 1050 and 1200 °C, with reheats planned into the sequence to hold finishing temperature.
Heat treatment in house
Solution treatment and precipitation ageing on site, chart recorded, with the traces issued against the heat number.
EN 10204 certification
Works certificates to 3.1, or 3.2 with third-party inspection, covering chemistry, mechanical results, heat treatment and dimensional reports.
Address and contact
Jiangyin Jiangnan Metal Co., Ltd.No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone, WhatsApp and WeChat: +86-189-2135-9659
Email: sales@steelforgepieces.com
Web: www.steelforgepieces.com
Enquiries
Send the grade, dimensions, quantity and delivery condition. Add the specification, ultrasonic acceptance class and certificate type if the project names them. A drawing is preferred. Quotations are normally issued within one working day.
Frequently asked questions
What is NiCr20TiAl?
NiCr20TiAl is the DIN and EN designation for a wrought, precipitation-hardenable nickel-chromium superalloy containing about 18 to 21 % chromium, 1.8 to 2.7 % titanium and 1.0 to 1.8 % aluminium, with nickel as the balance. It is the same material sold as Nimonic 80A or Alloy 80A, and is catalogued as UNS N07080 and Werkstoff number 2.4952, also 2.4631. Titanium and aluminium form gamma prime Ni₃(Al,Ti) precipitates during ageing, which give the alloy high tensile and creep-rupture strength together with good oxidation and corrosion resistance at temperatures up to 815 °C.
What is NiCr20TiAl equivalent to?
NiCr20TiAl is equivalent to Nimonic 80A, Alloy 80A, UNS N07080, Werkstoff 2.4952 and 2.4631, BS 3076 HR1 and the related HR201, HR401 and HR601 classes, AFNOR NC 20TA and the Chinese grade GH4080A. It is covered by DIN 17742, EN 10269, EN 10090, EN 10302 and ASTM B637 depending on the product form.
What is the chemical composition of NiCr20TiAl?
The composition of NiCr20TiAl per DIN 17742 is carbon 0.10 % max, chromium 18.0 to 21.0 %, titanium 1.8 to 2.7 %, aluminium 1.0 to 1.8 %, iron 3.0 % max, cobalt 2.0 % max, manganese 1.0 % max, silicon 1.0 % max, copper 0.2 % max, zirconium 0.15 % max, sulphur 0.015 % max, boron 0.008 % max and lead 0.0025 % max, with nickel as the balance.
What is the maximum service temperature of NiCr20TiAl?
NiCr20TiAl retains useful tensile and creep-rupture strength up to about 815 °C, or 1500 °F. The gamma prime strengthening phase coarsens and dissolves above roughly 800 to 850 °C, so continuous load-bearing service is normally limited to 815 °C. Short excursions and non-structural oxidation resistance extend somewhat higher.
What heat treatment is applied to NiCr20TiAl forgings?
The standard double heat treatment for NiCr20TiAl forgings is solution treatment at 1080 °C for 8 hours followed by air cooling, then precipitation ageing at 700 °C for 16 hours followed by air cooling. Jiangyin Jiangnan Metal Co., Ltd. carries out this cycle in house and supplies the furnace chart with each order.
Can NiCr20TiAl be welded?
Yes. NiCr20TiAl is weldable by TIG and MIG provided the material is in the solution-treated condition before welding. Nimonic 90 filler is the usual match. The weldment should be re-solution treated and re-aged afterwards to restore gamma prime strengthening and relieve residual stress.
What is the difference between Nimonic 80A and Nimonic 90?
Nimonic 80A, which is NiCr20TiAl or UNS N07080, contains a maximum of 2 % cobalt. Nimonic 90, UNS N07090 and Werkstoff 2.4632, contains roughly 15 to 21 % cobalt. The cobalt addition raises creep-rupture strength between 815 and 920 °C, so Nimonic 90 is chosen for hotter turbine sections. Nimonic 80A is used where cobalt must be kept low, in particular for nuclear components, and where alloy cost is a factor.
Who supplies NiCr20TiAl forged rings and discs in China?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China that produces NiCr20TiAl, also known as Alloy 80A and UNS N07080, as forged rings, seamless rolled rings, discs, shafts, flanges, round bars, sleeves, bushings and tube sheets to customer drawings. Enquiries go to sales@steelforgepieces.com or +86-189-2135-9659.
What testing and certification are supplied with NiCr20TiAl forgings?
NiCr20TiAl forgings are ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 at the acceptance class stated on the order. Material certificates are issued to EN 10204 3.1, or 3.2 with third-party inspection by bodies such as TUV, SGS, BV, Lloyd's Register or DNV. Chemical analysis, mechanical test results, heat treatment charts and dimensional reports are included in the documentation package.
What information is needed to quote a NiCr20TiAl forging?
To quote a NiCr20TiAl forging, send the drawing or the finished dimensions, meaning outside diameter, inside diameter and height or length, together with the quantity, the delivery condition as forged or rough or finish machined, the required specification and heat treatment condition, the ultrasonic acceptance class and the certificate type. A quotation from Jiangyin Jiangnan Metal Co., Ltd. normally follows within one working day.
About this datasheet
Published by Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China.
First published . Last reviewed .
Composition and property data are consolidated from DIN 17742, EN 10269 and published producer datasheets for Alloy 80A, and cross-checked against our own heat records. Figures are for guidance. The certified results for the supplied heat govern.
Citation
Jiangyin Jiangnan Metal Co., Ltd. (2026). NiCr20TiAl Forgings (Alloy 80A / UNS N07080): composition, properties and heat treatment. https://www.steelforgepieces.com/Nickel-Alloy/NiCr20TiAl.html