UNS N06601 Forgings: Alloy 601 Rings, Flanges, Shafts and Discs
UNS N06601, also designated Alloy 601, W.-Nr. 2.4851 and NiCr23Fe, is a nickel-chromium-iron alloy containing 1.0 to 1.7 % aluminium. It resists oxidation and carburisation in air up to approximately 1,200 °C (2,200 °F). Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. We produce UNS N06601 forged rings, seamless rolled rings, flanges, shafts, discs, sleeves and tube sheets to ASTM B564, supplied solution annealed with EN 10204 3.1 or 3.2 certification.
Last reviewed 29 August 2026. Prepared by the technical department, Jiangyin Jiangnan Metal Co., Ltd.
Description of UNS N06601
UNS N06601 is strengthened in solid solution and contains no precipitation hardening addition. The alloy carries 1.0 to 1.7 % aluminium. At service temperature this aluminium forms a thin aluminium oxide (Al2O3) film beneath the chromium oxide scale. The film remains adherent under thermal cycling and does not spall readily, which gives Alloy 601 a longer service life than plain nickel-chromium grades in furnace and burner applications.
The same oxide film reduces the rate of carbon pick-up. UNS N06601 is therefore specified for carburising atmospheres, including heat treating retorts, radiant tubes, muffles and catalyst support grids. The alloy also resists chloride ion stress corrosion cracking and corrosion by high purity water, and it retains ductility after long exposure at temperature.
Service limitation. UNS N06601 is not recommended for strongly reducing atmospheres containing sulphur. Nickel and sulphur form a low melting eutectic that attacks the alloy along grain boundaries. If the process gas contains H2S or SO2 under reducing conditions, please state this at the enquiry stage so that an appropriate grade can be proposed.
Equivalent designations for Alloy 601
The alloy appears under several designations in different national standards. All refer to the same composition. Jiangyin Jiangnan Metal Co., Ltd. certifies forgings against whichever designation is stated on the purchase order.
| System | Designation |
|---|---|
| UNS (USA) | N06601 |
| Werkstoff / DIN | 2.4851 |
| EN | NiCr23Fe |
| ISO | SNi6601 |
| BS (UK) | NA 49 |
| AFNOR (France) | NC23FeA |
| JIS (Japan) | NCF 601 |
| GOST (Russia) | KhN60VT / EI868 |
| Trade names | Inconel® 601, Alloy 601, Nicrofer 6023 |
| Welding consumable | AWS A5.14 ERNiCrFe-11 |
Governing product standards
- ASTM B564 / ASME SB-564, nickel alloy forgings. This is the standard we forge to.
- AMS 5715, bar, forgings and rings.
- ASTM B166, rod, bar and wire.
- ASTM B167, seamless pipe and tube.
- ASTM B168, plate, sheet and strip.
- ASME B16.5, ASME B16.47, EN 1092-1, flange dimensions.
Chemical composition of UNS N06601
The composition limits below are those of ASTM B564. Each heat forged by Jiangyin Jiangnan Metal Co., Ltd. is analysed by optical emission spectrometry. Ladle analysis and product analysis are both reported on the material test certificate.
| Element | Minimum | Maximum | Function in the alloy |
|---|---|---|---|
| Nickel (Ni) | 58.0 | 63.0 | Austenitic matrix, carburisation and stress corrosion resistance |
| Chromium (Cr) | 21.0 | 25.0 | Forms the chromium oxide scale, oxidation resistance |
| Aluminium (Al) | 1.0 | 1.7 | Forms the adherent Al2O3 film |
| Iron (Fe) | Balance, nominally 14 | Base element | |
| Carbon (C) | — | 0.10 | Restricted to limit carbide precipitation |
| Manganese (Mn) | — | 1.00 | Deoxidiser |
| Silicon (Si) | — | 0.50 | Deoxidiser |
| Copper (Cu) | — | 1.00 | Residual element |
| Sulphur (S) | — | 0.015 | Tramp element, restricted for hot workability |
| Narrower internal limits can be applied. State them on the purchase order and they will be written into the certificate. | |||
Mechanical properties of UNS N06601 forgings
Values apply to the solution annealed condition at room temperature. The minimum column is the acceptance requirement of ASTM B564. The typical column shows values normally obtained on heavy open-die forgings.
| Property | Minimum (ASTM B564) | Typical range |
|---|---|---|
| Tensile strength | 550 MPa / 80 ksi | 585 to 760 MPa |
| Yield strength, 0.2 % offset | 205 MPa / 30 ksi | 240 to 415 MPa |
| Elongation in 50 mm | 30 % | 35 to 55 % |
| Reduction of area | — | 45 to 70 % |
| Hardness | 161 HB max | 120 to 160 HB |
| Elevated temperature tensile and stress rupture data for a given section size can be issued with the quotation on request. | ||
Heat treatment note. UNS N06601 is a solid solution alloy with no age hardening response. A solution plus ageing cycle does not increase its strength and is not applicable to this grade. Forgings are supplied in the solution annealed condition. Strength can be raised only by cold work, which reduces ductility and is not normally applied to heavy forgings.
Physical properties of Alloy 601
| Property | Value | Condition |
|---|---|---|
| Density | 8.11 g/cm³ (0.293 lb/in³) | 20 °C |
| Melting range | 1,360 to 1,411 °C (2,480 to 2,571 °F) | — |
| Modulus of elasticity | 206 GPa | 20 °C |
| Thermal conductivity | 19.5 W/m·K | 500 °C |
| Coefficient of thermal expansion | 15.19 µm/m·°C | mean to 500 °C |
| Electrical resistivity | 1.24 µΩ·m | 500 °C |
| Magnetic response | Non-magnetic | annealed condition |
| Oxidation resistance in air | to approx. 1,200 °C (2,200 °F) | scale resistance limit |
UNS N06601 forged product forms
All items listed below are produced from forged bar or forged hollow. Castings and welded fabrications are not supplied as forgings.
Rings and rolled rings
Seamless rolled rings, forged rings, retaining rings and spacer rings, radial-axial rolled so that grain flow follows the circumference.
Flanges and tube sheets
Weld neck, blind, slip on, long weld neck and orifice flanges to ASME B16.5, ASME B16.47 and EN 1092-1, plus tube sheets and baffle plates for shell and tube exchangers.
Shafts, bars and spindles
Forged round bar, stepped shafts, eccentric shafts, spindles and pump plungers, supplied rough turned or finish machined to drawing.
Discs, blanks and gear blanks
Forged discs, blank discs, gear blanks, turbine blanks and wheel forgings produced by upsetting.
Sleeves, bushings and hollow bar
Bored and trepanned sleeves, bushings, cylinders and hollow bar, together with forged pipe and forged tube for high temperature service.
Valve and process components
Valve bodies, bonnets, stems, seat rings and blocks, nozzles, manifolds, crankshafts and crystalliser components.
Size and weight range
The table below covers the sizes normally produced in UNS N06601 at Jiangyin Jiangnan Metal Co., Ltd. Sizes outside this range may still be possible. Please send the drawing for confirmation.
| Form | Outside diameter | Length or height | Single piece weight |
|---|---|---|---|
| Seamless rolled rings | 200 to 2,500 mm | up to 1,000 mm | 5 to 4,000 kg |
| Forged discs and blanks | 100 to 2,000 mm | 30 to 500 mm thick | 5 to 4,000 kg |
| Shafts and round bar | 80 to 800 mm | up to 6,000 mm | 10 to 5,000 kg |
| Sleeves and hollow bar | 100 to 1,200 mm | up to 3,000 mm | 10 to 3,000 kg |
| Flanges | DN 15 to DN 2000 | per dimensional standard | 1 to 2,500 kg |
| Tube sheets | up to 2,500 mm | up to 400 mm thick | up to 5,000 kg |
| Machining allowance is agreed at the quotation stage. Forgings are supplied as forged, rough machined or finish machined. | |||
Manufacturing route for UNS N06601 forgings
The route below is applied to every UNS N06601 order at Jiangyin Jiangnan Metal Co., Ltd. Records from each stage are retained and issued with the certificate package.
- Melting and refining Electric arc furnace melting followed by AOD or VOD refining. Electroslag remelting is applied where the specification or the section size requires improved cleanliness and reduced segregation.
- Homogenisation and conditioning Soaking to reduce as cast segregation before the first reduction, then surface conditioning to remove defects that would otherwise be forged into the part.
- Open-die forging Hot working between approximately 1,040 °C and 1,180 °C, finishing above 980 °C. Material is reheated as required. Alloy 601 work hardens rapidly and will crack if forged below the safe finishing temperature.
- Ring rolling Radial-axial rolling for ring geometries, giving circumferential grain flow and more uniform wall thickness than a punched and drifted ring.
- Solution annealing Approximately 1,120 to 1,175 °C with soaking time in proportion to the governing section, followed by rapid cooling. Furnace charts are recorded for each batch.
- Rough machining Removal of the scaled and decarburised surface so that ultrasonic inspection is carried out on clean metal.
- Non-destructive testing Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, together with dye penetrant inspection of machined surfaces.
- Mechanical testing and certification Tensile testing, hardness testing and any specified supplementary tests, followed by EN 10204 3.1 or 3.2 documentation, marking, preservation and packing.
Testing and certification
Supplied as standard
- Chemical analysis, ladle and product, by optical emission spectrometry
- Room temperature tensile test and hardness survey
- Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, acceptance class as stated on the order
- Dye penetrant inspection of machined surfaces
- Dimensional report against the approved drawing
- EN 10204 3.1 material test certificate
Available on request
- EN 10204 3.2 certification witnessed by TÜV, SGS, BV, Lloyd's Register or the customer's own inspector
- Positive material identification on every piece
- Intergranular corrosion testing to ASTM A262
- Charpy impact testing, elevated temperature tensile testing, grain size and microstructure reports
- Hardness mapping, macro etch and step down testing
Please state the required ultrasonic acceptance class on the enquiry. Specifying a higher class than the application requires increases both cost and rejection rate. Our technical department reviews the specification before the order is confirmed.
Applications for UNS N06601 forgings by industry
Heat treatment and furnace equipment
Retorts, muffles, radiant tubes, burner components, fan shafts, roller hearths, baskets and fixtures. Cyclic heating combined with a carburising atmosphere is the principal application area for this alloy.
Chemical and petrochemical processing
Catalyst support grids in nitric acid plants, reactor internals, thermowells, columns and tower internals, preheaters, crystalliser components and process modules.
Power generation and energy
Superheater tube supports, combustor liners and transition components, gas turbine hardware, and forged rings and discs for gas compressors and turbines.
Pressure vessels and heat exchangers
Forged flanges, tube sheets, forged pipe and forged tube for shell and tube heat exchangers, air receivers and pressure vessels operating in the high temperature range.
Valves and rotating equipment
Valve bodies, seat rings, stems and blocks for gate, globe, ball, check and plug valves, together with pump shafts, plungers and impeller components for chemical and slurry pumps.
Waste incineration and cement
Grate bars, ash handling components, kiln hardware, mill parts and mixer components exposed to abrasive high temperature conditions.
Alloy 601 compared with 600, 625 and 800H
Grade selection is normally decided by service temperature, process atmosphere and required strength. The table below summarises how these four alloys differ.
| Alloy | Main composition | Approx. max continuous service in air | Typical selection basis |
|---|---|---|---|
| Alloy 601 N06601 |
Ni 58 to 63, Cr 21 to 25, Al 1.0 to 1.7 | approx. 1,150 °C | Cyclic oxidation and carburising atmospheres above about 1,040 °C |
| Alloy 600 N06600 |
Ni 72 min, Cr 14 to 17, Fe 6 to 10 | approx. 1,095 °C | Chloride stress corrosion cracking and caustic service, lower cost than Alloy 601 |
| Alloy 625 N06625 |
Ni 58 min, Cr 20 to 23, Mo 8 to 10, Nb 3.15 to 4.15 | approx. 980 °C | Higher strength together with aqueous and seawater corrosion resistance |
| Alloy 800H N08810 |
Ni 30 to 35, Cr 19 to 23, Fe balance | approx. 1,100 °C | Creep rupture strength at temperature at a lower alloy cost |
| Service limits are indicative for oxidising air. Reducing, sulphidising and halogen bearing atmospheres change them substantially. Please provide the process gas analysis for grade confirmation. | |||
Frequently asked questions about UNS N06601
What is UNS N06601?
UNS N06601 is a nickel-chromium-iron alloy containing 58.0 to 63.0 % nickel, 21.0 to 25.0 % chromium and 1.0 to 1.7 % aluminium, with iron as the balance. The aluminium forms an adherent aluminium oxide film that gives the alloy resistance to oxidation and carburisation in air up to approximately 1,200 °C (2,200 °F). The alloy is also designated Alloy 601, W.-Nr. 2.4851 and NiCr23Fe. Jiangyin Jiangnan Metal Co., Ltd. supplies UNS N06601 as open-die forgings and seamless rolled rings to ASTM B564.
Is UNS N06601 the same as Inconel 601?
Both designations describe the same alloy composition. UNS N06601 is the neutral UNS designation and Inconel® 601 is a registered trademark of Special Metals Corporation. Material ordered as UNS N06601 to ASTM B564 meets the same chemical and mechanical requirements. Jiangyin Jiangnan Metal Co., Ltd. certifies its forgings against UNS N06601 and W.-Nr. 2.4851.
What is the maximum service temperature of Alloy 601?
Alloy 601 resists oxidation in air up to approximately 1,200 °C (2,200 °F). Continuous service is normally limited to about 1,100 to 1,150 °C because load bearing strength falls at higher temperatures. The alloy is not recommended for strongly reducing atmospheres containing sulphur.
Which standard covers UNS N06601 forgings?
Forgings are supplied to ASTM B564, or to ASME SB-564 for pressure vessel code work, and to AMS 5715 for bar, forgings and rings. Related product standards are ASTM B166 for rod and bar, ASTM B167 for seamless pipe and tube, and ASTM B168 for plate, sheet and strip. Flange dimensions follow ASME B16.5, ASME B16.47 or EN 1092-1.
Can UNS N06601 be age hardened?
No. UNS N06601 is strengthened in solid solution and has no age hardening response, so an ageing cycle will not raise its strength. Forgings are supplied in the solution annealed condition. Strength can be increased only by cold work, which reduces ductility and is not normally applied to heavy forgings.
What heat treatment is applied to UNS N06601 forgings?
Solution annealing at approximately 1,120 to 1,175 °C, with soaking time in proportion to section thickness, followed by rapid cooling in water or forced air. Jiangyin Jiangnan Metal Co., Ltd. records a furnace chart for every heat treatment batch and issues it with the material test certificate.
What is the difference between Alloy 601 and Alloy 600?
Alloy 601 contains 1.0 to 1.7 % aluminium and 21.0 to 25.0 % chromium. Alloy 600 has no deliberate aluminium addition and 14.0 to 17.0 % chromium. The aluminium in Alloy 601 forms an oxide film that remains adherent under thermal cycling and slows carbon pick-up, so Alloy 601 is normally selected above about 1,040 °C and in carburising atmospheres. Alloy 600 has a higher nickel content and is preferred for chloride stress corrosion cracking resistance and caustic service.
What testing and certification is supplied with the forgings?
The standard scope is chemical analysis, room temperature tensile testing, hardness testing, ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, and dye penetrant inspection. Positive material identification, intergranular corrosion testing to ASTM A262 and impact testing are available on request. Certification is EN 10204 3.1 as standard, or EN 10204 3.2 witnessed by a third party such as TÜV, SGS, BV or Lloyd's Register.
How do I request a quotation for UNS N06601 forgings?
Send a drawing or the finished dimensions together with the quantity, the applicable specification and the required certification level to sales@steelforgepieces.com, or call +86-189-2135-9659. Jiangyin Jiangnan Metal Co., Ltd. is located at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, and quotes forgings in the as forged, rough machined or finish machined condition.
Title: UNS N06601 (Alloy 601) forgings: composition, properties
and supply.
Published by: Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory, No.1
Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China.
Contact: +86-189-2135-9659,
sales@steelforgepieces.com.
Last reviewed: 29 August 2026.
Reference:
https://www.steelforgepieces.com/Nickel-Alloy/UNS-N06601.html