Inconel 600
Complete analysis of Inconel 600 alloy (UNS N06600)
I. Implementation standards (by product form)
The technical specifications of Inconel 600 cover American standards, national standards and international systems, targeting different product forms:
- Plates/strips: ASTM B168 / ASME SB – 168 (specifies dimensions, performance and processing requirements);
- Bars/forging billets:
- Bars: ASTM B166 / ASME SB – 166;
- Forgings: ASTM B564 / ASME SB – 564 (general forging standard);
- Seamless pipes: ASTM B167 / ASME SB – 167;
- Welded pipes: ASTM B516 / ASME SB – 516, ASTM B517 / ASME SB – 517;
- Aerospace standards: AMS 5540 (bars), AMS 5665 (wires);
- Domestic equivalent: GB/T 15007 (corresponding to GH600 grade, belonging to China’s high – temperature alloy system).
II. Name and Code
- General name: Inconel 600;
- Authoritative identification:
- American standard: UNS No6600 (core number, internationally used);
- European standard: W.Nr. 2.4816 (Germany), NiCr15Fe (component abbreviation, highlighting the proportion of Cr and Fe);
- National standard: GH600 (Chinese high – temperature alloy grade);
- Other codes: NC15Fe in France, NA14 in the UK, NCF600 in Japan.
III. Chemical composition (mass fraction,%, typical range of ASTM standard)
Inconel 600 is a nickel – chromium – iron solid solution strengthened alloy, which improves corrosion resistance and high – temperature stability through the synergy of high Ni + Cr:
| Element | Content Range | Core Function |
|---|---|---|
| Nickel (Ni) | 72.0 – 76.0 | Matrix, resists corrosion, stabilizes austenite (resists stress corrosion cracking) |
| Chromium (Cr) | 14.0 – 17.0 | Resists oxidation (resists oxidizing media, such as nitric acid) and pitting corrosion |
| Iron (Fe) | 6.0 – 10.0 | Assists in strengthening, reduces cost (balances alloy density and strength) |
| Carbon (C) | ≤0.15 | Controls the precipitation of grain boundary carbides (Cr₇C₃) and avoids embrittlement |
| Manganese (Mn) | ≤1.0 | Improves hot working fluidity (inhibits hot cracking) |
| Silicon (Si) | ≤0.5 | Optimizes casting structure and inhibits impurity segregation |
| Copper (Cu) | ≤0.5 | Slightly improves corrosion resistance to reducing media (such as dilute sulfuric acid) |
| Sulfur (S) | ≤0.015 | Inhibits hot working cracks (reduces hot brittleness sensitivity) |
| Phosphorus (P) | ≤0.015 | Inhibits cold brittleness (maintains plasticity at low temperatures) |
IV. Mechanical properties (solid solution treatment state, typical value at room temperature)
After solution treatment (water quenching at 1050 – 1150°C), Inconel 600 achieves medium and high strength relying on solid solution strengthening, and can be stably used at -200 – 1000°C (no age hardening, high – temperature performance is maintained by solid solution):
| Performance Indicator | Typical Value (Solution State) | Remarks |
|---|---|---|
| Tensile Strength | ≥655 MPa | Can be further improved by cold working (e.g., reaches 800 MPa + after cold rolling) |
| Yield Strength (0.2%) | ≥240 MPa | High – temperature strength decreases slowly with the increase of temperature (still ≥200 MPa at 1000°C) |
| Elongation (%) | ≥30 | Excellent formability, supporting complex processing such as rolling and welding |
| Hardness (HB) | 150 – 220 | Soft state, convenient for mechanical processing (cutting/grinding) |
V. Heat Treatment Requirements
- Core Process: Solution Treatment
- Temperature: 1050 – 1150°C (hold for 1 – 2 hours to ensure uniform solid solution of Cr and Ni and inhibit the precipitation of harmful phases);
- Cooling: Water quenching or rapid air cooling (to prevent the precipitation of grain boundary carbides/metal intermetallic phases and ensure corrosion resistance and plasticity).
- Processing Auxiliary Points:
- Hot working: Temperature range 1100 – 1200°C (pass through quickly to avoid prolonged 停留 leading to grain coarsening and affecting plasticity);
- Cold working: Easy to form in the solution state, it is recommended that the single deformation amount ≤30% (excessive cold working requires intermediate annealing at 1050°C to restore plasticity and eliminate work hardening).
VI. Main application fields
Inconel 600, due to its “oxidation resistance/reduction corrosion + high – temperature stability + easy processing”, focuses on medium and high – temperature complex corrosion scenarios:
- Nuclear and Energy:
- Thermocouple sleeves and control rod guide tubes of nuclear reactors (resistant to high – temperature water and irradiation environment corrosion, long – term service below 1000°C);
- Linings and radiation tubes of heat treatment furnaces (resistant to carburizing/nitriding atmosphere, resistant to high – temperature oxidation, such as carburizing furnaces and nitriding furnaces).
- Chemical Industry:
- Chloride/fluoride production: Vinyl chloride monomer (resistant to Cl₂ and HCl corrosion), preparation of uranium hexafluoride (resistant to HF corrosion);
- Alkali metal sulfide environment: Preparation of sodium sulfide (resistant to the synergistic corrosion of strong alkali and sulfide, replacing stainless steel).
- Aerospace:
- Engine combustion chamber components and high – temperature fasteners (≤1000°C, resistant to fuel gas oxidation corrosion; strength improved after cold – working strengthening).
- Special Scenarios:
- Food processing (resistant to organic acids and high – temperature sterilization, such as sterilization kettle linings);
- Marine engineering (resistant to seawater/salt spray, low – stress environment, such as seawater cooling pipelines).
Supplementary Characteristics
- Corrosion resistance advantage: Resists both oxidizing media (concentrated nitric acid) and reducing media (dilute sulfuric acid) at the same time, and has extremely strong resistance to stress corrosion cracking (SCC);
- Weldability: Compatible with TIG and MIG welding, ERNiCr – 3 welding wire (AWS A5.14) is recommended, and no additional heat treatment is required for the welded state (performance can be maintained by solution – state welding);
- Differences from Inconel 600H:
- Inconel 600H: Strictly controls carbon content (≤0.10%) and grain size, and has better high – temperature creep performance above 700°C, suitable for long – term high – temperature load scenarios (such as petrochemical catalytic regenerators).
Inconel 600 is a “benchmark for medium and high – temperature general – purpose corrosion – resistant alloys”, and its core competitiveness lies in solid solution strengthening + wide – temperature – range corrosion resistance. When selecting materials, it is necessary to match standards (such as 600H focusing on long – term high – temperature service) based on temperature (≤1000°C), medium type (oxidizing/reducing), and stress level.