Inconel 601 vs 602 – What's the Difference
Due to the addition of aluminum (Al), Inconel 601 exhibits excellent high-temperature oxidation resistance, making it ideal for use in furnaces and kilns. Inconel 602 (typically 602CA), on the other hand, contains higher levels of nickel (Ni), chromium (Cr), and titanium (Ti), resulting in superior creep resistance, sulfidation resistance, and resistance to reducing atmosphere corrosion. Therefore, it is more suitable for the petrochemical industry and exhaust systems requiring extreme durability, especially in harsh, sulfur-rich, or low-oxygen environments. In short, 601 is suitable for high-temperature/oxidizing environments, while 602 is suitable for demanding chemical/sulfidizing environments.
Does Inconel 600 rust?
The high nickel content in the specified chemical composition of INCONEL 600 alloy enables it to resist corrosion from a wide variety of organic and inorganic compounds and makes it almost completely immune to chloride stress corrosion cracking.
Inconel 601 is a nickel-chromium-iron alloy strengthened and protected at high temperatures by the addition of aluminum. Its key characteristic is its exceptional resistance to oxidation, carburization, and sulfidation at extreme temperatures up to approximately 1250°C, while maintaining excellent high-temperature strength and thermal stability. It is designed for applications requiring long-term exposure to high-temperature corrosive atmospheres, such as high-temperature heat treatment equipment, industrial furnace components, combustion systems, petrochemical cracking tubes, and aerospace hot-end components. It is particularly suitable for harsh conditions involving alternating oxidation and reduction, making it a top-tier material for addressing high-temperature oxidation and thermal fatigue problems.
Inconel 602 is a nickel-chromium-iron alloy strengthened for ultra-high temperatures by the addition of higher levels of aluminum and yttrium. Its core characteristic is its unparalleled resistance to oxidation, carburization, and sulfidation at extreme temperatures up to approximately 1300°C, while maintaining excellent creep resistance and high-temperature stability. It is designed for ultra-high-temperature heat treatment furnaces, industrial combustion systems, petrochemical cracking units, and aerospace hot-end components that require long-term exposure to severe oxidizing-reducing atmospheres and thermal cycling. It excels in resistance to thermal cycling fatigue and high-temperature corrosion, making it a top-tier material for the most extreme high-temperature conditions.
Chemical composition of Inconel 601 and Inconel 602
| Element | Inconel 601 (UNS N06601) | Inconel 602 (UNS N06025) |
|---|---|---|
| Nickel (Ni) | 58.0 – 63.0 % | ≥ 60.0 % |
| Chromium (Cr) | 21.0 – 25.0 % | 24.0 – 26.0 % |
| Iron (Fe) | Balance | 8.0 – 11.0 % |
| Aluminum (Al) | 1.0 – 1.7 % | 1.8 – 2.4 % |
| Carbon (C) | ≤ 0.10 % | 0.15 – 0.25 % |
| Manganese (Mn) | ≤ 1.0 % | ≤ 0.50 % |
| Silicon (Si) | ≤ 0.5 % | ≤ 0.50 % |
| Copper (Cu) | ≤ 1.0 % | ≤ 0.50 % |
| Titanium (Ti) | ≤ 0.15 % | – |
| Zirconium (Zr) | – | 0.01 – 0.10 % |
| Yttrium (Y) | – | 0.05 – 0.12 % |
| Sulfur (S) | ≤ 0.015 % | ≤ 0.015 % |
| Phosphorus (P) | – | ≤ 0.020 % |
Mechanical properties of Inconel 601 and Inconel 602
| Property | Inconel 601 (Annealed) | Inconel 602 (Annealed) |
|---|---|---|
| Tensile Strength (MPa, min) | 655 – 895 | 650 – 850 |
| Yield Strength (0.2% Offset, MPa, min) | 345 | 300 – 400 |
| Elongation (% in 50 mm, min) | 30 | 30 |
| Hardness (Rockwell B) | 95 HRB max | 85 – 100 HRB |
| Hardness (Brinell HB) | 150 – 220 HB | 150 – 210 HB |
| Density (g/cm³) | 8.11 | 7.95 |
| Melting Range (°C) | 1300 – 1370 | 1350 – 1380 |
| Modulus of Elasticity (GPa) | 210 | 205 |
| Maximum Service Temperature (Continuous, in Air) | ~1250°C | ~1200°C |
| Thermal Conductivity (W/m·K, at 20°C) | 11.2 | 10.5 |
| Coefficient of Thermal Expansion (×10⁻⁶/K, 20–100°C) | 12.6 | 13.0 |
| Creep Resistance | Excellent | Outstanding |
| Oxidation Resistance | Excellent (high Al) | Exceptional (Al + Y/Zr) |
| Carburization Resistance | Good | Very Good |
| Thermal Fatigue Resistance | Good | Excellent |
| Impact Toughness (Charpy V-Notch, J) | Good | Good |
Corrosion Resistance:
One of the most important considerations when choosing an Inconel alloy is its corrosion resistance. Inconel 601 is known for its excellent corrosion resistance in various environments, including acidic environments. Its composition, which includes aluminum, makes it particularly suitable for sulfur-rich environments. On the other hand, Inconel 602 has inferior corrosion resistance compared to Inconel 601.
Heat Treatment:
An important characteristic of any high-temperature alloy is its ability to withstand thermal cycling. Inconel 601 exhibits excellent heat resistance, capable of withstanding temperatures up to 1150°C. It can also be easily welded using conventional methods, making it a common choice for manufacturing components in high-temperature environments. In contrast, Inconel 602 has limited heat treatment capabilities and is not recommended for high-temperature applications.
Inconel 601 and 602 Application Comparison
Given these differences, Inconel 601 and 602 each have their specific application areas. Inconel 601 is commonly used in high-temperature furnace components, heat treatment equipment, and other industrial applications requiring extremely high oxidation resistance. It maintains its structural integrity even at extreme temperatures, making it a reliable choice in these demanding environments.
On the other hand, Inconel 602 is more suitable for applications requiring both oxidation and sulfidation resistance. This alloy is commonly found in petrochemical processing equipment, exhaust systems, and other areas frequently exposed to reducing atmospheres and sulfide environments.
Why Choose Gnee as Your Nickel-Based Alloy Supplier
✅ Over 18 years of export experience, products sold to more than 80 countries
✅ Certified by ISO, SGS, and BV
✅ Global inventory of Inconel, Hastelloy, Incoloy, and Monel alloy tubing, plates, and bars
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📦 Packaging and Shipping
All stainless steel products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
Gnee Steel is a supplier of inconel 601 alloy, offering a wide range of products including: seamless pipe (sizes: 4-219 mm; thickness: 0.5-20 mm); welded pipe (sizes: 5.0-1219.2 mm; thickness: 0.5-20 mm); plates (thickness: 0.1 to 100 mm; width: 10-2500 mm); strips; alloy round bars (diameter: 3-800 mm); flat bars (thickness: 2-100 mm; width: 10-500 mm); hexagonal bars (size: 2-100 mm); wire rods; and extruded profiles. We collaborate with steel mills to provide our customers with inconel 601 alloy products that meet or exceed numerous leading industry standards, including ASTM, ASME, SAE, AMS, ISO, DIN, EN, and BS standards.
Gnee Steel stocks and sells inconel 601, pipes, plates, strips, round bars, flat bars, forged billets, hexagonal steel, wire rods, and extruded profiles. Please feel free to contact us at ss@gneesteel.com for a quote.
