What is NiCr20Co11Mo10TiAl?
NiCr20Co11Mo10TiAl is a DIN style designation. The name lists the main elements: a nickel base with about 19 % chromium, 11 % cobalt and 10 % molybdenum, plus titanium and aluminium. The same alloy is sold as Rene 41 and registered as UNS N07041 and Werkstoff 2.4973. It was developed by General Electric in the 1950s and was used for the outer shell of the Mercury space capsule.
Strength comes from gamma prime, Ni3(Al,Ti), which precipitates during ageing. Cobalt and molybdenum give solid solution strengthening, and boron and carbon at the grain boundaries improve creep and rupture life. The alloy is stronger than Inconel 718 above about 700 °C and carries load up to about 980 °C.
It is not an easy alloy to process. The forging temperature window is narrow, it is difficult to machine, and it is sensitive to strain age cracking when welded. Parts in this grade are normally open die forged or ring rolled rather than cut from plate.
Other spellings of the same grade. The alloy also appears on drawings as NiCr19Co11Mo10Ti3, Alloy 41, Alloy R-41 or Rene 41. All of them are UNS N07041. Because acceptance criteria differ between AMS, GE and customer specifications even when the chemistry is the same, the purchase order should always name the specification and its edition.
NiCr20Co11Mo10TiAl equivalents and specifications
The table matches a drawing callout to the grade we forge. Cross references are for identification only. The specification named on your order governs acceptance.
| System | Designation | Scope |
|---|---|---|
| DIN / EN name | NiCr20Co11Mo10TiAl | Also written NiCr19Co11Mo10Ti3 |
| Werkstoff Nr. | 2.4973 | European material number |
| UNS | N07041 | Unified Numbering System, USA |
| AISI | 683 | Older US designation |
| AFNOR | NCK19DTA | French designation |
| Trade names | Rene 41, Haynes R-41, Pyromet Alloy 41, CarTech 41 | Producer brand names for the same chemistry |
| SAE AMS 5712 | AMS 5712 | Bar, forgings and rings. The usual specification for forged parts |
| SAE AMS 5713 | AMS 5713 | Bar and forgings, vacuum melted material |
| SAE AMS 5545 | AMS 5545 | Sheet, strip and plate |
| SAE AMS 5800 | AMS 5800 | Welding wire |
| GE specifications | B50T59, B50TF76, B50TF109 | Engine maker specifications for forgings, bar and sheet |
If you are choosing between this grade and Waspaloy, Nimonic 263 or Inconel 718, see the grade comparison below.
Chemical composition of NiCr20Co11Mo10TiAl (UNS N07041)
Ladle analysis limits in weight percent. The actual analysis of each heat is printed on the material certificate.
| Element | Symbol | Min % | Max % | Function |
|---|---|---|---|---|
| Nickel | Ni | Balance | Matrix, host for the gamma prime phase | |
| Chromium | Cr | 18.00 | 20.00 | Oxidation and hot corrosion resistance |
| Cobalt | Co | 10.00 | 12.00 | Raises the gamma prime solvus, solid solution strengthening |
| Molybdenum | Mo | 9.00 | 10.50 | Solid solution strengthening, creep resistance |
| Titanium | Ti | 3.00 | 3.30 | Gamma prime former, Ni3(Al,Ti) |
| Aluminium | Al | 1.40 | 1.80 | Gamma prime former, oxide film at temperature |
| Carbon | C | 0.06 | 0.12 | Grain boundary carbides |
| Boron | B | 0.003 | 0.010 | Grain boundary strengthening, rupture life |
| Iron | Fe | - | 5.00 | Residual |
| Silicon | Si | - | 0.50 | Residual, deoxidation |
| Copper | Cu | - | 0.50 | Residual |
| Manganese | Mn | - | 0.10 | Residual |
| Sulphur | S | - | 0.015 | Impurity, kept low for hot workability |
Tighter limits, for example S below 0.005 % or a controlled Ti and Al ratio, can be agreed at order stage and written into the melting instruction.
Mechanical and physical properties
Room temperature mechanical properties
| Property | Typical value | Condition |
|---|---|---|
| Tensile strength Rm | 1415 MPa (205 ksi) | Solution treated and aged |
| Proof strength Rp0.2 | 1050 MPa (152 ksi) | Solution treated and aged |
| Elongation A | 19 % | Solution treated and aged |
| Hardness | 35-40 HRC | Aged |
| Elastic modulus E | about 220 GPa (32 x 106 psi) | 20 °C |
These values are for guidance. Certified properties depend on the heat, the section size and the heat treatment route, and are reported on the EN 10204 certificate for each order.
Behaviour at temperature
This grade is bought for what it does hot. At 650 °C it still reaches over 1000 MPa tensile strength. At 870 °C strength is around half the room temperature value, which is still enough for loaded engine hardware. Oxidation resistance and resistance to jet combustion gases are good up to about 980 °C. Above that, strength falls off quickly and a cast or coated alloy is normally used instead.
Physical properties
| Property | Value |
|---|---|
| Density | 8.25 g/cm3 (0.298 lb/in3) |
| Melting range | 1307-1343 °C (2385-2450 °F) |
| Maximum service temperature, oxidation | about 980 °C (1800 °F) |
| Useful strength range | 650-980 °C (1200-1800 °F) |
| Magnetic response | Non magnetic at room temperature |
Heat treatment of NiCr20Co11Mo10TiAl forgings
Two routes are in common use. Route A gives better creep rupture strength and room temperature ductility. Route B gives higher tensile and yield strength. We run the route named on the drawing and supply the furnace charts with the certificate.
| Route | Solution treatment | Ageing | Result |
|---|---|---|---|
| A, high solution | 1177 °C (2150 °F), 4 h, air cool | 900 °C (1650 °F), 4 h, air cool | Better creep rupture strength and room temperature ductility |
| B, low solution | 1066-1080 °C (1950-1975 °F), 4 h, air cool | 760 °C (1400 °F), 16 h, air cool | Higher tensile and yield strength |
The 650-930 °C range needs care. Gamma prime precipitates in this range, so cold worked or welded sections must be heated quickly through it on the way to solution temperature. Slow heating through the ageing range is a common cause of strain age cracking in this grade.
Forgings are normally supplied solution treated, or solution treated and aged. Test coupons are taken from prolongations that go through the same heat treatment charge as the parts they represent.
NiCr20Co11Mo10TiAl forged forms and size range
We forge NiCr20Co11Mo10TiAl to drawing. The ranges below are what we run regularly in this grade. Larger sizes are checked case by case against ingot size and press capacity.
| Forged form | Size range | Used for |
|---|---|---|
| Seamless rolled rings | OD 150-2500 mm, height to 600 mm, wall from 25 mm | Turbine casings, mount rings, retaining rings |
| Open die forged rings | OD to 2000 mm, wall from 30 mm | Short run rings, heavy wall spacers |
| Flanges and flange blanks | OD to 1800 mm | Hot gas duct joints, high temperature closures |
| Round bars and billets | Dia. 60-600 mm, length to 4000 mm | Bolting stock, machined engine hardware |
| Discs and blanks | Dia. to 1500 mm, thickness 25-500 mm | Wheels, seal plates, turbine discs |
| Shafts and spindles | Dia. 80-600 mm, length to 4000 mm | Hot service rotating shafts, spindles |
| Sleeves and bushings | OD 150-1500 mm | Wear sleeves, hot section bushings |
| Tube sheets and plates | To 2000 mm across | High temperature exchangers, headers |
| Valve bodies, seat rings, blocks | To drawing | Hot service valve internals |
| Forged weight per piece | 3 kg to 2000 kg | Heavier pieces on enquiry |
Delivery conditions
- As forged, descaled, for customers who machine and heat treat in house.
- Rough machined to a stated allowance, normally 5 to 20 mm per side depending on size and section.
- Solution treated, or solution treated and aged to route A or route B above.
- Finish machined to drawing, including bores, faces and grooves, on request.
Minimum order is one piece. We take prototypes and single spare parts, and we keep the forging drawing and the process record for repeat orders.
From ingot to certified forging
- Melting. The alloy is melted by EAF and VOD, then refined by ESR to control gas content and segregation. Double and triple melted material (VIM + VAR, or VIM + ESR + VAR) is arranged when an aerospace specification such as AMS 5713 calls for vacuum melted stock.
- Homogenising and cogging. Ingots are homogenised and cogged to billet. The reduction ratio is recorded so the finished part meets the minimum forging ratio on the specification.
- Forging. Billets are heated to about 1150 °C and worked with the finishing temperature kept above about 950 °C, with reheats as needed. Working the alloy too cold cracks it, working it too hot coarsens the grain, so every heat is logged.
- Ring rolling. Rings are punched, expanded and rolled. This gives grain flow that follows the circumference, which is why a rolled ring performs better in hot loaded service than a ring machined from plate.
- Heat treatment. Solution treatment and ageing to the route named on the order, in furnaces with calibrated and recorded temperature control.
- Machining. Rough or finish machining in house to the agreed allowance.
- Testing and inspection. Chemical analysis, room temperature tensile and hardness, grain size to ASTM E112, and ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388. Elevated temperature tensile, stress rupture, impact, dye penetrant and dimensional reports are added when specified.
- Certification and dispatch. EN 10204 3.1 mill certificate as standard, or EN 10204 3.2 witnessed by TUV, SGS, BV, DNV or Lloyd's Register. Parts are hard stamped or vibro marked with heat number and drawing number and packed in wooden cases for sea or air freight.
Traceability. Heat number, forging record, furnace chart, NDT report and certificate stay linked to the piece from ingot to packing list, so a part can be traced years after delivery.
Where NiCr20Co11Mo10TiAl forgings are used
The alloy is specified where a part has to stay strong and dimensionally stable in a hot gas stream or under sustained load at temperature.
| Industry | Forged parts |
|---|---|
| Aero engines | Turbine casings and rings, nozzle partitions, afterburner components, combustion chamber hardware, turbine wheels, high temperature fasteners |
| Airframe and space | High speed airframe structure, rocket and missile components, skins and structural hardware exposed to aerodynamic heating |
| Industrial gas turbines and power | Casing rings, seal plates, hot section bolting, springs and retaining hardware |
| Oil, gas and petrochemical | Valve bodies, seat rings and stems for hot service, shafts and sleeves for high temperature pumps and compressors |
| Process and chemical plant | Flanges, tube sheets and nozzles on high temperature vessels and exchangers |
| Heavy machinery and tooling | Hot service dies, mandrels and press tooling that has to resist softening |
Machining, welding and handling
Machining
NiCr20Co11Mo10TiAl work hardens quickly and is classed as difficult to machine. Use carbide tooling, rigid fixturing, positive and uninterrupted feed, plenty of coolant and a modest surface speed. Where the drawing allows it, rough machine in the solution treated condition and take finishing cuts after ageing to hold size.
Welding
The alloy is sensitive to strain age cracking because of its aluminium and titanium content. Weld in the fully solution treated condition. Resistance welding and electron beam welding give the fewest problems. For GTAW, keep the joint tightly fitted and use copper backing or water cooled fixtures. After welding, solution treat the assembly with fast heating and cooling through the 650-870 °C range, then age. AMS 5800 is the matching filler wire.
Cold work
Cold reductions should be substantial rather than light sizing passes, with frequent intermediate anneals. Ageing after light cold work invites cracking. Heat quickly through the ageing range to the solution temperature instead.
NiCr20Co11Mo10TiAl compared with similar alloys
A short guide for buyers deciding between grades. We forge all four.
| Grade | UNS | Hardened by | Working ceiling | Notes |
|---|---|---|---|---|
| NiCr20Co11Mo10TiAl (Rene 41) | N07041 | Gamma prime Ni3(Al,Ti) | about 980 °C | Highest strength of the four, hardest to weld and machine |
| Waspaloy | N07001 | Gamma prime Ni3(Al,Ti) | about 760 °C | Very strong, easier to fabricate than Rene 41 |
| Inconel 718 | N07718 | Gamma double prime Ni3Nb | about 650 °C | Weldable, widely stocked, lower cost |
| Nimonic 263 | N07263 | Gamma prime, lower volume fraction | about 850 °C | Formable and weldable, used for fabricated sheet structures |
The ceilings are working guidance for loaded parts, not specification limits. Below about 650 °C, Inconel 718 is usually cheaper and faster to get. Above about 700 °C with high stress, NiCr20Co11Mo10TiAl is the stronger choice.
How to get a price for NiCr20Co11Mo10TiAl forgings
A dimensioned sketch is enough to start. A drawing gets you a firm price.
- Send the drawing or the dimensions. A 2D drawing, a 3D model, or OD x ID x height for a ring, or diameter x length for a bar or shaft.
- Name the grade and the standard. NiCr20Co11Mo10TiAl, Rene 41, UNS N07041 or W.Nr. 2.4973, plus the governing specification such as AMS 5712 or your own company specification.
- State the condition and the test scope. As forged, rough machined, solution treated, or solution treated and aged, and which tests and certificate you need (EN 10204 3.1 or 3.2, ultrasonic class, elevated temperature tensile, stress rupture).
- Get the quotation within 24 hours. You receive unit price, forged weight, lead time and the proposed inspection plan in one email.
Request a quotation
Jiangyin Jiangnan Metal Co., Ltd. is an open die forging factory in Jiangyin, Jiangsu, China, supplying forged rings, rolled rings, flanges, bars, discs and shafts in nickel alloys, stainless steel, tool steel, alloy steel and carbon steel. Quotations go out within 24 hours. Production lead time for NiCr20Co11Mo10TiAl is normally 30 to 50 days.
Company
Jiangyin Jiangnan Metal Co., Ltd.
Open die forging factory
Address
No.1 Chengxiqiao Road,
Zhouzhuang Town, Jiangyin City,
Jiangsu Province, China
Phone and WhatsApp
NiCr20Co11Mo10TiAl questions we are asked
What is NiCr20Co11Mo10TiAl?
NiCr20Co11Mo10TiAl is the DIN style name for a precipitation hardening nickel chromium cobalt molybdenum alloy, better known as Rene 41, UNS N07041 and W.Nr. 2.4973. It contains about 19 % chromium, 11 % cobalt, 10 % molybdenum, 3 % titanium and 1.6 % aluminium, with nickel as the balance. It holds high strength between about 650 °C and 980 °C and is used for jet engine hot parts, turbine casings, missile components, high temperature bolting and springs.
Is NiCr20Co11Mo10TiAl the same as Rene 41?
Yes. NiCr20Co11Mo10TiAl, Rene 41, Alloy R-41, Haynes R-41, Pyromet Alloy 41, CarTech 41, AISI 683, AFNOR NCK19DTA, UNS N07041 and W.Nr. 2.4973 are the same alloy. The composition limits are the same, but acceptance criteria differ between specifications, so the purchase order should name the exact standard, for example AMS 5712 for bar and forgings.
What is the chemical composition of NiCr20Co11Mo10TiAl?
Chromium 18.0-20.0 %, cobalt 10.0-12.0 %, molybdenum 9.0-10.5 %, titanium 3.0-3.3 %, aluminium 1.4-1.8 %, carbon 0.06-0.12 %, boron 0.003-0.010 %, iron 5.0 % max, silicon 0.50 % max, manganese 0.10 % max, sulphur 0.015 % max, copper 0.50 % max, nickel balance. The full table is above on this page.
What heat treatment is used for NiCr20Co11Mo10TiAl forgings?
Two routes are in common use. Solution treatment at about 1177 °C for 4 hours and air cooling, followed by ageing at about 900 °C for 4 hours, gives the best creep rupture strength and room temperature ductility. Solution treatment at about 1080 °C for 4 hours followed by ageing at about 760 °C for 16 hours gives higher tensile strength. The cycle follows the drawing or the governing specification.
What sizes of NiCr20Co11Mo10TiAl forgings can be supplied?
Jiangyin Jiangnan Metal Co., Ltd. supplies NiCr20Co11Mo10TiAl as seamless rolled rings from about 150 mm to 2500 mm outside diameter, round bars from about 60 mm to 600 mm diameter, discs and blanks up to about 1500 mm diameter and shafts up to about 4000 mm long, with forged weights from a few kilograms up to about 2000 kg per piece. Larger sizes are checked case by case.
Which certificates and tests come with the forgings?
Each order is delivered with an EN 10204 3.1 mill certificate, or a 3.2 certificate witnessed by a third party such as TUV, SGS, BV, DNV or Lloyd's Register. Standard testing covers chemical analysis, room temperature tensile and hardness, grain size and ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388. Elevated temperature tensile, stress rupture and dye penetrant testing are available on request.
Why is NiCr20Co11Mo10TiAl difficult to weld?
The alloy is hardened by aluminium and titanium, so it is sensitive to strain age cracking. Gamma prime precipitates during the weld thermal cycle and embrittles the heat affected zone. Weld in the fully solution treated condition, heat and cool quickly through the ageing range, then solution treat and age the assembly again. Resistance welding and electron beam welding give the fewest problems.
What is the lead time for NiCr20Co11Mo10TiAl forgings?
A written quotation is sent within 24 hours of receiving the drawing. Production lead time is normally 30 to 50 days from order confirmation, depending on ingot availability, the number of forging and heat treatment cycles and the machining scope. Single piece trial orders are accepted.
About Jiangyin Jiangnan Metal Co., Ltd.
Jiangyin Jiangnan Metal Co., Ltd. is an open die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, in the Yangtze River delta forging cluster about two hours by road from the port of Shanghai. We forge rings, seamless rolled rings, flanges, round bars, discs, shafts, sleeves, bushings and tube sheets in carbon steel, alloy steel, tool steel, stainless steel and nickel alloys, and export to buyers in Europe, North America, the Middle East, India, Japan, Korea, Southeast Asia and Australia.
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Made to drawing
No catalogue minimums. One piece prototypes and repeat production go through the same documented process.
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Certificates
EN 10204 3.1 as standard. 3.2 witnessed by TUV, SGS, BV, DNV or Lloyd's Register on request.
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Testing
Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, plus mechanical, grain size and PT reports.
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Quotation time
Drawings quoted within one working day, in English, with forged weight and lead time stated up front.
To discuss a NiCr20Co11Mo10TiAl forging, email sales@steelforgepieces.com, call +86 189 2135 9659, or use the contact page.