Inconel 600 – UNS N06600
Solid-solution-strengthened nickel-chromium-iron alloy
Ni-Cr-Fe alloy with at least 72% nickel, for general use at high temperature and in moderately corrosive media. It combines good resistance to oxidation, alkaline media (caustic soda) and chloride stress corrosion cracking. Not hardenable by heat treatment: strength increases only by cold work.
Designations and equivalents
| System | Designation |
|---|---|
| UNS | N06600 |
| W.Nr./EN | 2.4816 – NiCr15Fe |
| DIN | NiCr15Fe (DIN 17742) |
| JIS | NCF 600 |
| Trade names | Inconel 600 (Special Metals), Nicrofer 7216 (VDM), Alloy 600 |
| Others | AMS 5540 (plate), AMS 5665 (bar) |
Standards by product form
| Form | Standard |
|---|---|
| Bar | ASTM B166 |
| Forging | ASTM B564 |
| Plate | ASTM B168 |
| Tube | ASTM B167 (seamless), B163 (heat exchanger) |
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 / B564 (UNS N06600)
| Element | Range (%) |
|---|---|
| Ni (+Co) | ≥ 72.0 |
| Cr | 14.0 – 17.0 |
| Fe | 6.0 – 10.0 |
| C | ≤ 0.15 |
| Mn | ≤ 1.00 |
| Si | ≤ 0.50 |
| Cu | ≤ 0.50 |
| S | ≤ 0.015 |
Mechanical properties
annealed (ASTM B564 / B166 hot rolled and annealed)
| Property | Value |
|---|---|
| Yield strength (0.2%) | ≥ 241 MPa |
| Tensile strength | ≥ 552 MPa |
| Elongation | ≥ 30% |
| Hardness (typical, annealed) | ≈ 75 – 95 HRB |
Typical physical properties
| Property | Value |
|---|---|
| Density | 8.47 g/cm³ |
| Melting range | 1,354 – 1,413 °C |
| Modulus of elasticity | 207 GPa |
| Thermal conductivity (20 °C) | 14.9 W/m·K |
| Thermal expansion (20–100 °C) | 13.3 µm/m·K |
| Electrical resistivity | 103 µΩ·cm |
Heat treatment, welding and machining
| Item | Usual practice |
|---|---|
| Service temperature | Oxidation resistance up to ~1,100 °C; creep design typically up to ~650 °C. In sulfur-bearing atmospheres the limit drops considerably (typically ~550 °C). |
| Heat treatment | Supplied annealed (≈ 980 – 1,040 °C) or solution annealed (≈ 1,120 °C, when creep resistance is sought), with rapid cooling. Avoid long solution-annealing times (grain growth). Not age hardenable. |
| Welding | Good weldability by GTAW, GMAW and SMAW. Consumables: AWS A5.14 ERNiCr-3 (FM 82 type) and AWS A5.11 ENiCrFe-3 (182 type). Normally without preheat or PWHT. |
| Machining | Low machinability: work hardens quickly; use sharp carbide, constant feed (no 'rubbing') and abundant coolant. |
Filler metal for welding
The wire composition is usually not identical to the material: each page explains why.
Typical applications
- Muffles, retorts and fixtures for heat treatment furnaces
- Heat exchangers and heaters in the chemical industry
- Evaporators and caustic soda equipment
- Fatty acid and food processing
- Thermocouple sheaths and heating elements
- Nuclear components (replaced by 690 in primary water)
Alternatives: Inconel 601 for cyclic oxidation above ~1,050 °C; Incoloy 800H/HT when cost and creep weigh more; Inconel 690 in pressurized water (nuclear); Nickel 201 for hot concentrated caustic soda.
Inconel 600: complete guide
What Inconel 600 is
Inconel 600 belongs to the family of nickel alloys, in the solid-solution nickel-chromium-iron group. With a minimum of 72% nickel, it resists reducing media, caustics and chloride stress corrosion cracking; with 14 to 17% chromium, it resists oxidation in air up to about 1,100 °C. It does not harden by heat treatment: its strength comes from solid solution and cold work.
Mechanical properties
In annealed bar and forgings, ASTM B166 / B564 requires a minimum yield strength of 241 MPa, minimum tensile strength of 552 MPa and minimum elongation of 30%. Under load at temperature, design is based on creep allowable stresses, typically up to about 650 °C; oxidation resistance, up to 1,100 °C, applies to lightly loaded components.
Welding
Good weldability by TIG, MIG and covered electrode with ERNiCr-3 and ENiCrFe-3 consumables, without preheat or post-weld heat treatment.
Corrosion and limits of use
600 is the classic alloy for caustic soda and alkaline media, magnesium chloride and reducing processes, and resists chloride stress corrosion cracking well.
Applications
Muffles, retorts, baskets and heat treatment furnace components, caustic soda production and concentration equipment, exchangers and vessels for reducing chemical processes, turbine and engine components at moderate temperature, glass furnace parts and food equipment.
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 600?
Per ASTM B166 / B564 (UNS N06600): Ni (+Co) ≥ 72.0; Cr 14.0 – 17.0; Fe 6.0 – 10.0; C ≤ 0.15; Mn ≤ 1.00; Si ≤ 0.50.
Which standards cover Inconel 600?
Bar: ASTM B166. Forging: ASTM B564. Plate: ASTM B168. Tube: ASTM B167 (seamless), B163 (heat exchanger).
Up to what temperature can Inconel 600 be used?
Oxidation resistance up to ~1,100 °C; creep design typically up to ~650 °C. In sulfur-bearing atmospheres the limit drops considerably (typically ~550 °C).
Which materials can replace Inconel 600?
Inconel 601 for cyclic oxidation above ~1,050 °C; Incoloy 800H/HT when cost and creep weigh more; Inconel 690 in pressurized water (nuclear); Nickel 201 for hot concentrated caustic soda.
