Inconel 601 – UNS N06601
Nickel-chromium-iron alloy with aluminum for high-temperature oxidation
Ni-Cr-Fe alloy with an aluminum addition, which forms a very adherent oxide layer resistant to thermal cycling. It is chosen for oxidation and carburization up to ~1,200 °C. Not hardenable by heat treatment.
Designations and equivalents
| System | Designation |
|---|---|
| UNS | N06601 |
| W.Nr./EN | 2.4851 – NiCr23Fe |
| DIN | NiCr23Fe |
| JIS | NCF 601 |
| Trade names | Inconel 601 (Special Metals), Nicrofer 6023 (VDM), Alloy 601 |
| Others | AMS 5715 (plate) |
Standards by product form
| Form | Standard |
|---|---|
| Bar | ASTM B166 |
| Forging | ASTM B166 (forged bar); B564 does not cover N06601 |
| Plate | ASTM B168 |
| Tube | ASTM B167 (seamless), B163 |
Tolerances and HS codes
- Forged bars (round and square): machining allowance from 2 mm (Ø 6–16 mm) to 24 mm (Ø 400–500 mm) on the diameter. E.g. Ø 100–125 mm finished: +7 mm, tolerance +6 / −0 (length up to 3,500 mm).
- Forged discs: allowance of 4 to 9 mm on the diameter and 3 to 11 mm on the height, plus-only tolerance.
- Cutting and machining: band saw −0 / +5 to +15 mm on length; waterjet +10 % of thickness on the diameter (min. 2 mm); machined parts −0 / +2 to +5 mm on the diameter. See the full tables (INF 002 and INF 003, the same for every alloy).
| Form | NCM (Brazil, 8 digits) | HS (international, 6 digits) | HTS (USA, 10 digits)* | CN (European Union, 8 digits)* |
|---|---|---|---|---|
| Forged bar | 7505.12.10 | 7505.12 | 7505.12.3000 | 7505 12 00 |
| Hot-rolled bar | 7505.12.10 | 7505.12 | 7505.12.3000 | 7505 12 00 |
| Plate (> 10 mm, width ≥ 600 mm) | 7506.20.00 | 7506.20 | 7506.20.3000 | 7506 20 00 |
| Seamless pipe | 7507.12.00 | 7507.12 | 7507.12.0000 | 7507 12 00 |
| Welded pipe | 7507.12.00 | 7507.12 | 7507.12.0000 | 7507 12 00 |
| Flange and fitting | 7507.20.00 | 7507.20 | 7507.20.0000 | 7507 20 00 |
Tariff class: nickel alloy (by chemical composition, under the Chapter 72 Notes and Section XV Note 5).
*: US and EU codes for reference. NCM per current legislation (General Rules of Interpretation, Notes to Chapters 72, 74 and 75 and Section XV Note 5). Confirm the final code with your customs broker according to the item size and finish. HS = first 6 digits of the NCM.
Chemical composition (%)
ASTM B166 / B168 (UNS N06601)
| Element | Range (%) |
|---|---|
| Ni | 58.0 – 63.0 |
| Cr | 21.0 – 25.0 |
| Fe | balance (≈ 14) |
| Al | 1.0 – 1.7 |
| C | ≤ 0.10 |
| Mn | ≤ 1.0 |
| Si | ≤ 0.50 |
| Cu | ≤ 1.0 |
| S | ≤ 0.015 |
Mechanical properties
annealed (ASTM B166)
| Property | Value |
|---|---|
| Yield strength (0.2%) | ≥ 205 MPa |
| Tensile strength | ≥ 550 MPa |
| Elongation | ≥ 30% |
Typical physical properties
| Property | Value |
|---|---|
| Density | 8.11 g/cm³ |
| Melting range | 1,360 – 1,411 °C |
| Modulus of elasticity | 207 GPa |
| Thermal conductivity (20 °C) | 11.2 W/m·K |
| Thermal expansion (20–100 °C) | 13.8 µm/m·K |
| Electrical resistivity | 119 µΩ·cm |
Heat treatment, welding and machining
| Item | Usual practice |
|---|---|
| Service temperature | Oxidation, including cyclic, up to ~1,200 °C; mechanical strength drops considerably above ~760 °C. |
| Heat treatment | Supplied annealed (≈ 1,040 – 1,150 °C, typical), with rapid cooling. Not age hardenable. |
| Welding | Good weldability. Usual consumables: AWS ERNiCr-3 / ENiCrFe-3; for severe oxidation service above ~1,000 °C, ERNiCrCoMo-1 (617 type), typical. |
| Machining | Similar to Inconel 600: work hardens, requires carbide, low speed and good coolant. |
Filler metal for welding
The wire composition is usually not identical to the material: each page explains why.
Typical applications
- Furnace radiant tubes, muffles and retorts
- Baskets and grids for heat treatment (carburizing)
- Thermocouple sheaths
- Catalyst support grids in nitric acid
- Combustion chambers and burners
- Incinerator components
Alternatives: Inconel 600 when the temperature is lower and the medium is alkaline; Incoloy 800HT for creep at lower cost; alloys 602CA / 617 / HR-160 in more severe oxidation, carburization or sulfidation.
Inconel 601: complete guide
What Inconel 601 is
Inconel 601 belongs to the family of nickel alloys, in the nickel-chromium-iron group for high temperature. It is an evolution of Inconel 600 with more chromium and an aluminum addition: the chromium and aluminum oxide that forms on the surface is more adherent and resists heating and cooling cycles better, which gives the alloy the best cyclic oxidation resistance among the common Inconels. The structure is austenitic, face-centered cubic, stable and not hardenable by heat treatment.
Chemical composition and role of the elements
Nickel from 58 to 63%, chromium from 21 to 25% and aluminum from 1.0 to 1.7%, with iron as the balance, about 14%.
Mechanical properties
Annealed, ASTM B166 requires a minimum yield strength of 205 MPa, minimum tensile strength of 550 MPa and minimum elongation of 30%. Under load at temperature, design is based on creep allowable stresses.
Corrosion and limits of use
Exceptional resistance to oxidation in air up to about 1,200 °C, including thermal cycling, and good resistance to carburization and nitriding. Like all high-nickel alloys, it is limited in reducing sulfur-bearing atmospheres, where Incoloy 800HT or AISI 446 are better. In aqueous corrosion it behaves like 600, with good resistance to caustics and stress corrosion cracking.
Applications
Muffles, retorts and radiant tubes of industrial furnaces, heat treatment baskets, grids and fixtures, burner and incinerator components, thermocouple protection tubes, pollution control and high-temperature oxide production equipment, glass and ceramic furnace components.
Supply forms and Dustre services
Round bars and blocks forged in open die, cut to size on a band saw, with rough or finish machining, solution annealing or annealing in our own furnaces and hardness, tensile and impact testing. All material is supplied with a 3.1 inspection certificate and heat traceability.
Frequently asked questions
What is the chemical composition of Inconel 601?
Per ASTM B166 / B168 (UNS N06601): Ni 58.0 – 63.0; Cr 21.0 – 25.0; Fe balance (≈ 14); Al 1.0 – 1.7; C ≤ 0.10; Mn ≤ 1.0.
Which standards cover Inconel 601?
Bar: ASTM B166. Forging: ASTM B166 (forged bar); B564 does not cover N06601. Plate: ASTM B168. Tube: ASTM B167 (seamless), B163.
Up to what temperature can Inconel 601 be used?
Oxidation, including cyclic, up to ~1,200 °C; mechanical strength drops considerably above ~760 °C.
Which materials can replace Inconel 601?
Inconel 600 when the temperature is lower and the medium is alkaline; Incoloy 800HT for creep at lower cost; alloys 602CA / 617 / HR-160 in more severe oxidation, carburization or sulfidation.
