Physical properties
| Density | 8.415 | g/cm³ |
Informative values: they vary with composition, condition and test method. Use the governing standard or measured mill data for pressure and heat-transfer calculations.
Chemical composition
Nominal: mid-range where both limits are given, the cap where only a maximum is, balance takes the remainder. Exact specified ranges below.
| Element | Name | Content % | |
|---|---|---|---|
| Main elements4 elements | |||
| Ni | Nickel | 58 – 63% | |
| Cr | Chromium | 21 – 25% | |
| Fe | Iron | Bal. | |
| Al | Aluminium | 1 – 1.7% | |
| Element | Name | Content % | |
|---|---|---|---|
| Minor & residual5 elements | |||
| C | Carbon | ≤ 0.1% | |
| Mn | Manganese | ≤ 1% | |
| Cu | Copper | ≤ 1% | |
| Si | Silicon | ≤ 0.5% | |
| S | Sulphur | ≤ 0.015% | |
Mechanical minima by form
Guaranteed values differ by form, size and delivery condition; quotations confirm the specification, form, size and condition.
| Form | Condition | Rm MPa | Rp0.2 MPa | A ≥ % | Other requirements and notes |
|---|---|---|---|---|---|
| Bar and forgings | |||||
| Bar and rod | Annealed after cold working or after hot working | ≥ 550 (80 ksi) | ≥ 205 (30 ksi) | ≥ 30 | |
| Plate, sheet and strip | |||||
| Hot-rolled plate and sheet | Annealed | ≥ 550 (80 ksi) | ≥ 205 (30 ksi) | ≥ 30 | |
| Tube and pipe | |||||
| Seamless pipe and tube | Annealed after cold or hot working | ≥ 550 (80 ksi) | ≥ 205 (30 ksi) | ≥ 30 | |
| Seamless heat-exchanger tube | Annealed | ≥ 552 (80 ksi) | ≥ 207 (30 ksi) | ≥ 30 | |
| Welded heat-exchanger and condenser tube | Annealed (Class 1 or Class 2 — see note) | ≥ 550 (80 ksi) | ≥ 205 (30 ksi) | ≥ 30 | Every piece is leak- or electrically tested (hydrostatic, pneumatic, eddy current or ultrasonic). Flattening and flange tests required. |
| Several forms | |||||
| Flat products ≤75 mm and bars ≤160 mm (EN 10095) | +AT (solution annealed) | 550 – 750 | ≥ 205 | ≥ 30 | Wire rod (≤25 mm): only the tensile strength applies. |
Alloy 601's room-temperature yield minimum is 205 MPa, below the 240 MPa of alloy 600 — do not carry alloy 600's pressure-design data over to 601 just because 601 resists oxidation better.
Hardness requirement
Required by the standard, conditionally
| Form and thickness | Hardness max |
|---|---|
| Sheet; strip >0.25–3.2 mm | ≤ 86 HRB |
| Strip 0.13–0.25 mm | ≤ 88 HRB |
Likewise limited to cold-rolled deep-drawing and spinning-quality sheet and strip; ordinary plate, sheet and strip carry NO hardness requirement.
More detail 2
This is a hardness CEILING — deep-drawing material must be soft enough to form — the opposite in kind to the floor carried by age-hardened grades.
Under 1.3 mm the Rockwell B reading is affected by specimen thickness; use superficial Rockwell or Vickers instead.
Creep behaviour
Guidance values (MPa) — Mean values of a scatter band. They are neither an acceptance requirement nor a design allowable stress. Figures in parentheses are long-term extrapolations and less reliable than the tested range.
| Temp °C | Rupture strength Ru | ||
|---|---|---|---|
| 1 000 h | 10 000 h | 100 000 h | |
| 600 | 264 | 205 | 156 |
| 700 | 153 | 101 | 55 |
| 800 | 60 | 31 | 17 |
| 900 | 20 | 10 | 4 |
| 1000 | — | 5 | 2 |
Pressure design must take allowable stresses from the governing code (EN 13445, ASME and the like).
⚠ This grade carries rupture guidance only — there are no 1 % creep-elongation strength figures. Parts where the deflection has to be controlled need a manufacturer's creep curve instead.
⚠ EN 10095's composition differs from the same-named ASTM grade in one substantive way: EN sets a carbon MINIMUM. The EN 10095 grade requires C 0.03-0.10 %, whereas ASTM N06601 specifies only a carbon maximum. The reason is that this specification is written for heat-resisting service, and carbon is what supplies high-temperature creep strength — material low in carbon creeps sooner. ⚠ The creep data in this section therefore applies to material that meets that carbon floor. Same-grade material supplied to ASTM with carbon below it cannot simply be read off this table. For heat-resisting service, write the carbon minimum into the contract.
⚠ The maximum application temperature in air, Tₐ = 1 200 °C, is an oxidation criterion, not a load-bearing one. It means the metal loss from scaling does not exceed 1 g/(m²·h) at Tₐ, and does not exceed 2 g/m² on average at Tₐ + 50 °C over 120 h with four intermediate coolings. That is the highest of the nickel alloys in this table (600 is 1 150 °C, 625 only 1 000 °C). Alloy 601 forms an alumina scale from its 1.00-1.70 % aluminium and does oxidise less than 600, but the table above shows its rupture strength above 700 °C is not much higher than 600's.
Grain size
Required by the standard, conditionally
| Form and thickness | ASTM micrograin size | Mean grain section dia. |
|---|---|---|
| Sheet ≤1.3 mm | No. 4.5 or finer | ≤ 0.075 mm |
| Sheet >1.3–6.4 mm | No. 3.5 or finer | ≤ 0.110 mm |
| Strip 0.13–0.25 mm | No. 8 or finer | ≤ 0.022 mm |
| Strip >0.25–3.2 mm | No. 4.5 or finer | ≤ 0.075 mm |
Applies only to COLD-ROLLED DEEP-DRAWING AND SPINNING QUALITY sheet and strip.
More detail 4
If the order does not call for that quality, this table does not apply.
For this product class, grain size and hardness REPLACE the ordinary tensile minima — the tensile minima do not apply to it, and vice versa.
The direction is "or finer" (a maximum grain diameter), the opposite of 800H's "No. 5 or coarser": deep drawing needs fine grain against orange peel, creep needs coarse grain.
Strip over 3.2 mm thick or over 305 mm wide is judged on the sheet rows; under 0.13 mm, testing is not recommended.
Where this grade is recommended
Matched in 7 service conditions; ranks and scores computed from the condition-scoring matrix.
| Service condition | Industry | Temperature | Rank | Score |
|---|---|---|---|---|
| Furnace internals & fixtures | Furnaces & Vacuum | ≤ 900 °C | 1 / 12 | 93 |
| Muffles & radiant tubes | Furnaces & Vacuum | 850 – 1000 °C | 3 / 9 | 92 |
| Quench & carburising fixtures | Furnaces & Vacuum | 850 – 950 °C | 1 / 8 | 90 |
| Exhaust systems & converters | Automotive & Racing | 400 – 700 °C | 1 / 5 | 88 |
| SOFC interconnects | Hydrogen & New Energy | 600 – 850 °C | 1 / 4 | 88 |
| DeNOx SCR & ducting | Environmental & FGD | 400 – 550 °C | 2 / 5 | 86 |
| Waste-to-energy boilers | Environmental & FGD | 450 – 700 °C | 4 / 8 | 85 |
Designations & equivalents
| W.Nr. (Germany) | 2.4851 |
| EN designation | NiCr23Fe |
| Trade name(s) | Inconel 601 / Nicrofer 6023 |
| ASTM / AISI | B163 / B166 / B167 / B168 / B516 / B751 / B775 / B829 |
| AMS (SAE aerospace) | 5715 / 5870 |
Cross-references are common near-equivalents for search and shortlisting; substitution across standards requires clause-by-clause verification. All grades in one cross-reference table →
Applicable standards
8 specifications. Name the standard and its edition on the order.
Guaranteed values and required tests differ between specifications — see Mechanical minima by form for the figures per form.
Frequently asked questions
What is Alloy 601 · UNS N06601?
Alloy 601 · UNS N06601 — Ni superalloys. Oxidation-resistant grade — furnace rolls and radiant tubes to about 1100 °C
What is the maximum service temperature of N06601?
Typically about 1100 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.
What is the tensile strength of N06601?
The specified minimum tensile strength is 550 MPa for the main product form. Minima for other forms and sizes are listed under "Mechanical minima by form" on this page.
Which standards cover N06601?
ASTM B163, ASTM B166, ASTM B167, ASTM B168, ASTM B516, AMS 5715, AMS 5870, EN 10095 (heat-resisting steels and nickel alloys)
Where is N06601 typically used?
Furnace internals & fixtures (Furnaces & Vacuum); Muffles & radiant tubes (Furnaces & Vacuum); Quench & carburising fixtures (Furnaces & Vacuum); Exhaust systems & converters (Automotive & Racing)
In which forms is N06601 available?
Tube, plate, strip, bar, forgings, wire and other forms — sizes and delivery condition confirmed per order, with EN 10204 3.1 / 3.2 certification.
Same series
Download PDF datasheet
This grade’s datasheet as an A4 PDF — for filing, printing or forwarding to colleagues.
Download PDF datasheetSupply & enquiry
Tube & pipeφ1 – 219 × 0.25 – 25 mm
Plate4.76 – 80 mm
Barφ8 – 300 mm
Wire & filler metalsφ0.01 – 8 mmFor this grade we can supply, against your service conditions:
- Tube, plate, strip, bar, forgings, wire and more — with size range and lead time
- Chemistry and mechanical test report (EN 10204 3.1 / 3.2)
- Like-for-like alternatives and selection advice
- Applicable standards and inspection scope
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