NiCr23Co12Mo Forgings Alloy 617, UNS N06617, W.Nr. 2.4663. Forged rings, discs, shafts, flanges and bars, solution annealed and ultrasonically tested.
- EN / DIN
- NiCr23Co12Mo
- Werkstoff
- 2.4663
- UNS
- N06617
- Common name
- Alloy 617
- Trade name
- Inconel 617
- ISO
- NiCr22Co12Mo9
NiCr23Co12Mo is the European (EN/DIN) designation for the nickel-chromium-cobalt-molybdenum superalloy also sold as Alloy 617 and Inconel 617. The same material carries Werkstoff number 2.4663 and UNS number N06617. It is strengthened by solid solution rather than by precipitation hardening, and it holds creep-rupture strength and resists oxidation and carburisation in continuous service to about 1100 °C (2012 °F). The strength comes from about 12 % cobalt and 9 % molybdenum in a 22 % chromium nickel matrix. Around 1 % aluminium forms the protective alumina-rich surface oxide.
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu, China. We produce NiCr23Co12Mo (Alloy 617) forged rings, seamless rolled rings, discs, shafts, flanges, sleeves, bushings, tube sheets and bars to customer drawings, supplied solution annealed, ultrasonically tested to EN 10228-3, and certified to EN 10204 3.1 or 3.2.
NiCr23Co12Mo forgings at a glance
The information most buyers ask for before sending a drawing.
| Material | NiCr23Co12Mo · W.Nr. 2.4663 · UNS N06617 · Alloy 617 · Inconel 617 |
|---|---|
| Alloy family | Solid-solution-strengthened Ni-Cr-Co-Mo superalloy, not age hardening |
| Forging method | Open-die forging (free forging) and seamless ring rolling |
| Piece weight | 1 kg to 8 000 kg per piece |
| Rolled ring size | OD 150 to 3 000 mm, height up to 800 mm |
| Bar and shaft size | Ø 40 to 800 mm, length up to 6 000 mm |
| Melting route | EAF + AOD/VOD + ESR. VIM + ESR or VIM + VAR available for aerospace-grade cleanliness |
| Delivery condition | Solution annealed and rapidly cooled. Black forged, rough turned or finish machined |
| Forging standards | ASTM B564 / ASME SB-564 · ASTM B166 / SB-166 · AMS 5887 · AMS 5888 · DIN 17752 / 17754 · VdTÜV 485 · EN 10302 |
| NDT | Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388. Penetrant to ASTM E165. Hardness and dimensional report |
| Certification | EN 10204 3.1 mill test certificate as standard. EN 10204 3.2 with third-party witness (TÜV, BV, SGS, DNV, Lloyd’s) on request |
| Minimum order | One piece. Prototypes and single spares accepted, no tooling charge |
| Typical lead time | 25 to 45 days ex works, depending on size and heat treatment |
| Made in | No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China |
The sizes above are our normal working envelope. Larger and heavier pieces are quoted case by case. Send the drawing and we will confirm feasibility in writing.
NiCr23Co12Mo chemical composition
Two specifications are commonly quoted for this grade and their limits are not identical. The European route (VdTÜV Data Sheet 485 and EN, for W.Nr. 2.4663) runs a narrower band and adds trace-element limits for arsenic, bismuth and lead. The American route (ASTM B564 and ASTM B166 for UNS N06617) is wider on chromium, cobalt and carbon. State which specification your drawing calls out. We certify to the one named on the order, and both sets of limits can be met together where they overlap.
| Element | EN 2.4663 · NiCr23Co12Mo | ASTM B564 · UNS N06617 |
|---|---|---|
| Ni, Nickel | Balance | 44.5 min |
| Cr, Chromium | 20.0 to 23.0 | 20.0 to 24.0 |
| Co, Cobalt | 10.0 to 13.0 | 10.0 to 15.0 |
| Mo, Molybdenum | 8.0 to 10.0 | 8.0 to 10.0 |
| Al, Aluminium | 0.60 to 1.50 | 0.80 to 1.50 |
| C, Carbon | 0.050 to 0.100 | 0.05 to 0.15 |
| Ti, Titanium | 0.20 to 0.50 | 0.60 max |
| Fe, Iron | 2.00 max | 3.00 max |
| Mn, Manganese | 0.70 max | 1.00 max |
| Si, Silicon | 0.70 max | 1.00 max |
| Cu, Copper | not specified | 0.50 max |
| B, Boron | not specified | 0.006 max |
| S, Sulphur | 0.008 max | 0.015 max |
| P, Phosphorus | 0.012 max | not specified |
| As, Arsenic | 0.010 max | not specified |
| Bi, Bismuth | 0.001 max | not specified |
| Pb, Lead | 0.007 max | not specified |
Limits are quoted from the referenced specifications for guidance. The edition of the standard named on the purchase order governs, and the ladle analysis on the mill test certificate issued with the goods is the binding document.
Mechanical properties of NiCr23Co12Mo forgings
The values below apply to material in the solution-annealed and rapidly cooled condition, tested at room temperature. Room-temperature strength is modest because the alloy is strengthened by solid solution. This grade is normally selected for its behaviour above 700 °C rather than for its cold properties.
| Property | ASTM B564 minimum | Typical forged value |
|---|---|---|
| Tensile strength Rm | 655 MPa / 95 ksi | 755 MPa / 109.5 ksi |
| Yield strength Rp0.2 | 240 MPa / 35 ksi | 385 MPa / 55.6 ksi |
| Elongation A5 | 35 % min | 56 % |
| Reduction of area Z | not specified | about 50 % |
| Hardness | not specified | about 193 HB |
High-temperature behaviour
Load-bearing capability extends well beyond the range of austenitic stainless steels and iron-nickel grades. The design points our customers work to:
- Continuous service to about 1100 °C for oxidation and carburisation resistance in flowing hot gas.
- Creep-governed design above about 700 °C. This is where Alloy 617 is normally selected over Alloy 800H or 253MA.
- ASME Section VIII, Division 1 lists allowable stresses for N06617 into the 1800 °F (982 °C) range, which is why the grade appears in ultra-supercritical boiler and advanced reactor work.
- Ductility is retained after long exposure, unlike many gamma-prime strengthened grades that embrittle after thousands of hours at temperature.
Relaxation cracking
Solution-annealed and welded Alloy 617 fabrications can be susceptible to relaxation cracking, also called reheat cracking, when heavy sections are restrained during first heat-up. If the part will be welded into a restrained assembly, say so at enquiry stage. Grain size targets and post-forge cooling can then be agreed before the ingot is cut.
Physical properties of NiCr23Co12Mo (2.4663)
| Property | Metric | Imperial |
|---|---|---|
| Density | 8.36 g/cm³ | 0.302 lb/in³ |
| Melting range | 1332 to 1380 °C | 2430 to 2516 °F |
| Modulus of elasticity at 20 °C | 211 GPa | 30.6 × 10³ ksi |
| Thermal conductivity at 20 °C | 13.4 W/m·K | 93 BTU·in/h·ft²·°F |
| Mean thermal expansion 20 to 100 °C | 11.6 µm/m·K | 6.4 µin/in·°F |
| Specific heat at 20 °C | 419 J/kg·K | 0.100 BTU/lb·°F |
| Electrical resistivity at 20 °C | 1.22 µΩ·m | 733 Ω·circ mil/ft |
| Magnetic permeability | about 1.0007, non-magnetic | Curie point below −190 °C |
How we forge NiCr23Co12Mo
The hot-working window for this grade is narrow and the alloy work-hardens quickly. Finished grain size determines whether a part passes ultrasonic inspection, so the schedule is controlled from reheat through to quench.
- ESR ingotEAF + VOD + ESR
- Reheat1150 to 1200 °C
- Upset and drawfinish above 950 °C
- Punch and ring rollseamless rolled ring
- Solution anneal1177 °C min, water quench
- UT and certificateEN 10228-3, EN 10204 3.1
Melting and stock
NiCr23Co12Mo billet is procured EAF + AOD/VOD + ESR remelted as standard. For rotating and aerospace parts we source VIM + ESR or VIM + VAR double-melt stock and pass the melt certificate through unchanged.
Hot-working window
Heavy reductions are taken between 1010 °C and 1205 °C. Light finishing passes run down to about 950 °C. Below that temperature the piece returns to the furnace rather than being worked further.
Deformation ratio
We hold a minimum 3:1 forging reduction ratio from ingot to finished section, and higher on rings, so the as-cast structure is fully broken down and the flow lines follow the part contour.
Solution annealing
ASTM B564 calls for solution annealing at a minimum of 1177 °C (2150 °F) followed by a water quench or equally rapid cooling. We soak to section thickness and quench. A slow cool will not meet the specification or the creep requirement.
Machining allowance
Supplied black forged, rough turned, or fully machined to drawing. Nickel superalloys move during annealing, so the machining allowance is agreed at order stage.
Traceability
Heat number, forging lot and part number are hard stamped or vibro-etched on every piece and reconciled against the mill test certificate before release.
NiCr23Co12Mo product forms we forge
All items below are produced by open-die forging or seamless ring rolling to your drawing. There is no fixed catalogue and no tooling charge.
Rings and seamless rolled rings
NiCr23Co12Mo forged rings, seamless rolled rings, retaining rings, shroud rings, guide rings and ring-shaped combustor hardware, OD 150 to 3000 mm.
Discs, blanks and hubs
Forged discs, forged blanks, gear blanks, turbine discs, hub forgings and circular plates, solid or trepanned.
Shafts, bars and spindles
Forged round bars, stepped shafts, eccentric shafts, spindles, valve stems and pump shafts, Ø 40 to 800 mm.
Flanges and tube sheets
Forged flanges in weld neck, slip-on and blind form, forged tube sheets and heat-exchanger tube plates for pressure equipment.
Sleeves, bushings and tubes
Forged sleeves, bushings, hollow bars and forged tubes with bored or trepanned bores.
Valve and near-net shapes
Valve bodies, valve blocks, seat rings, nozzles, manifolds, blocks and custom near-net-shape forgings.
Where NiCr23Co12Mo forgings are used
This grade is specified where a part runs continuously above 700 °C in an oxidising or carburising gas stream. Typical end uses:
Gas turbines
Combustion cans, transition ducts, liners, guide and shroud rings, turbine discs and rotor components.
Power generation
Ultra-supercritical boiler headers and connectors, high-temperature piping components, advanced reactor internals.
Petrochemical and refining
Reformer and cracking furnace hardware, catalyst supports, hot transfer piping, high-temperature valves.
Heat-treatment plant
Furnace retorts, muffles, fixtures, baskets, radiant tubes and rolls running in carburising atmospheres.
Chemical process
Nitric acid plant components, calciners, reaction vessel internals, columns, towers and preheaters.
Oil, gas and offshore
Wellhead and Christmas-tree components, valve bodies, flare tips and subsea hardware in hot sour service.
Aerospace
Engine casing rings, exhaust and afterburner hardware, ducting components to AMS 5887 and AMS 5888.
Heavy machinery
Compressor and gearbox components, calciner rolls, mill and mixer parts, crankshafts and forged rolls.
Pulp, paper and pharmaceutical
Digester and dryer hardware, crystalliser equipment and process modules needing hot corrosion resistance.
NiCr23Co12Mo compared with other high-temperature alloys
Alloy 625 and Alloy 718 carry more load at moderate temperature, but their strength falls away above about 800 °C. Alloy 617 and Alloy 230 retain useful properties at 1000 °C and above. The table sets out the practical selection points.
| Grade | UNS | Strengthening | Max continuous service | Choose it when |
|---|---|---|---|---|
| NiCr23Co12Mo, Alloy 617 | N06617 | Solid solution, Co and Mo | about 1100 °C | Creep strength and oxidation resistance are both needed above 900 °C. |
| Inconel 625 | N06625 | Solid solution, Mo and Nb | about 980 °C | Aqueous and seawater corrosion resistance dominates and temperature is secondary. |
| Inconel 718 | N07718 | Gamma-prime precipitation | about 700 °C | Very high strength is needed but service stays below 700 °C. |
| Haynes 230 | N06230 | Solid solution, W and Mo | about 1150 °C | Long-term thermal stability and lower cobalt content are preferred. |
| Incoloy 800H | N08810 | Solid solution, Fe-Ni-Cr | about 900 °C | Budget matters more than peak temperature and loads are modest. |
| Hastelloy X | N06002 | Solid solution, Mo and Cr | about 1090 °C | Sheet-metal fabricability in combustors outweighs peak creep strength. |
Maximum service temperatures are oxidation-limited guidance figures for lightly loaded parts, not design allowables. Creep-governed design must use the code allowable stress for the section and design life.
Testing, inspection and certification
Chemical analysis
Ladle analysis reported on the mill certificate. Product analysis by OES and combustion analysis on request, reported against the specification named on the order.
Mechanical testing
Tensile (Rm, Rp0.2, A, Z), hardness, and Charpy impact where specified. Test location and orientation per your standard, from prolongation or sacrificial ring.
Ultrasonic testing
Volumetric UT to EN 10228-3, SEP 1921 or ASTM A388, with the acceptance class agreed before forging starts.
Surface NDT
Liquid penetrant to ASTM E165 or EN 571-1 as standard for nickel alloys. Magnetic particle inspection does not apply because the grade is non-magnetic.
Grain size and metallography
ASTM E112 grain size, macro-etch and microstructure examination where the drawing or code requires it.
Certificates
EN 10204 3.1 mill test certificate with every shipment. EN 10204 3.2 with TÜV, BV, SGS, DNV or Lloyd’s witness on request. PED 2014/68/EU and NACE MR0175 documentation supported.
How to order NiCr23Co12Mo forgings
- Send the drawing or the finished dimensions. PDF, DWG, STEP or a dimensioned sketch all work. With no drawing, send OD by ID by height, or diameter by length.
- Name the specification. ASTM B564 / ASME SB-564, VdTÜV 485, DIN 17752 or AMS 5888, whichever your code requires. If you are not sure, tell us the operating temperature and pressure and we will propose one.
- State the delivery condition. Black forged, rough machined or finish machined, and whether the solution anneal is to be certified.
- List the testing and certificate level. UT class, impact requirement, EN 10204 3.1 or 3.2, third-party witness.
- We quote within 24 hours with price, forged weight, lead time and the standards we will certify to.
Frequently asked questions about NiCr23Co12Mo
Is NiCr23Co12Mo the same as Inconel 617?
Yes. NiCr23Co12Mo is the EN/DIN composition-based designation for the alloy sold under the trade name Inconel 617 and known generically as Alloy 617. The same material carries Werkstoff number 2.4663, UNS number N06617, ISO designation NiCr22Co12Mo9 and British designation NA 50. Inconel is a registered trademark of Special Metals Corporation. Material we supply is certified to the ASTM, EN or VdTÜV specification named on your order, not to a trademark.
What is the UNS number and Werkstoff number for NiCr23Co12Mo?
The UNS number is N06617 and the Werkstoff (W.Nr.) number is 2.4663, sometimes written 2.4663a. Both refer to the same nickel-chromium-cobalt-molybdenum superalloy.
What is the maximum service temperature of NiCr23Co12Mo?
About 1100 °C (2012 °F) for oxidation and carburisation resistance in continuous service. For load-bearing design the limit is creep rather than oxidation. ASME Section VIII Division 1 publishes allowable stresses for N06617 into the 982 °C (1800 °F) range. Above roughly 700 °C, design should be based on creep-rupture data for the section thickness and required service life, not on room-temperature strength.
Which standard covers NiCr23Co12Mo forgings?
The primary specification for forgings is ASTM B564 / ASME SB-564, which covers Ni-Cr-Co-Mo alloy N06617. Related specifications include ASTM B166 / SB-166 for rod and bar, ASTM B168 / SB-168 for plate, sheet and strip, ASTM B546 for welded pipe, AMS 5887 and AMS 5888 for aerospace product forms, DIN 17752 and DIN 17754 for rod and bar, VdTÜV Data Sheet 485, and EN 10302 for creep-resisting steels and nickel alloys.
What heat treatment do NiCr23Co12Mo forgings receive?
Solution annealing at a minimum of 1177 °C (2150 °F) per ASTM B564, held for a time appropriate to section thickness, then water quenched or otherwise rapidly cooled. Alloy 617 is strengthened by solid solution, so there is no ageing step in the standard condition. A subsequent age would not raise strength the way it does on Inconel 718 or Waspaloy.
What is the difference between Alloy 617 and Inconel 625?
Both are solid-solution nickel alloys with 20 to 23 % chromium and 8 to 10 % molybdenum. Alloy 617 adds 10 to 15 % cobalt plus about 1 % aluminium, while Inconel 625 adds 3 to 4 % niobium instead. The cobalt and aluminium give Alloy 617 better creep strength and oxidation resistance above roughly 900 °C. Inconel 625 is usually the better choice where aqueous, seawater or chloride corrosion resistance dominates and service temperature is moderate.
Is NiCr23Co12Mo magnetic?
No. With a relative permeability of about 1.0007 and a Curie point below −190 °C, the alloy is effectively non-magnetic at all normal service temperatures. Surface NDT on these forgings is therefore done by liquid penetrant rather than magnetic particle inspection.
What is the density of NiCr23Co12Mo?
8.36 g/cm³, equal to 0.302 lb/in³. The melting range is 1332 to 1380 °C (2430 to 2516 °F).
Can you supply NiCr23Co12Mo seamless rolled rings?
Yes. Seamless rolled rings are one of our core products. We roll NiCr23Co12Mo rings from OD 150 mm to OD 3000 mm with heights up to 800 mm, supplied solution annealed and ultrasonically tested. Rectangular, contoured and stepped ring profiles are all possible. Send the ring section drawing for a quotation.
What certificates do you provide with NiCr23Co12Mo forgings?
An EN 10204 3.1 mill test certificate is issued with every shipment as standard, covering ladle chemistry, heat treatment record, mechanical test results, NDT results, dimensional report and heat traceability. EN 10204 3.2 certificates with third-party witness by TÜV, BV, SGS, DNV or Lloyd’s Register are available on request and should be stated at enquiry stage so the inspection can be scheduled.
What is the minimum order quantity and lead time?
There is no minimum quantity. We accept single-piece orders, prototypes and one-off spares, and there is no tooling charge for open-die work. Typical lead time is 25 to 45 days ex works depending on piece size, machining scope and whether third-party inspection is required. Confirmed lead time is given with the quotation.
Who supplies NiCr23Co12Mo (Alloy 617) open-die forgings 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, producing NiCr23Co12Mo (Alloy 617 / UNS N06617 / W.Nr. 2.4663) forged rings, seamless rolled rings, discs, shafts, flanges, sleeves, bushings, tube sheets and bars to customer drawings. Contact: +86 189 2135 9659, sales@steelforgepieces.com, www.steelforgepieces.com.
Get a NiCr23Co12Mo quotation within 24 hours
Send your drawing, or just the dimensions and the specification. We reply with price, forged weight, lead time and the standards we will certify to, in writing and with no obligation.