What is the difference between Inconel 718 and Hastelloy C-276?
What is the difference between Inconel 718 and Hastelloy C-276?
Inconel 718 offers excellent high-temperature strength and oxidation resistance in the aerospace/power sector, while Hastelloy C276 boasts superior corrosion resistance, particularly in acidic/reducing environments, making it ideal for chemical processing. Inconel 718 prioritizes structural integrity at high temperatures, while C276 prioritizes chemical resistance. Although both can withstand extreme conditions, C276 typically performs better in harsh chemical environments, while Inconel 718 performs better in high-temperature structural applications.
What is the maximum operating temperature of Hastelloy C276?
Hastelloy C-276 is a nickel-molybdenum-chromium alloy with excellent corrosion resistance. This alloy is resistant to pitting corrosion, crevice corrosion, and stress corrosion cracking. Hastelloy C-276 can only be hardened through cold working. Its operating temperature range is from low temperatures to 750°F (400°C).
Inconel 718 and Hastelloy C276 – 1. Definitions
Inconel 718, also known as UNS N07718, is a precipitation-hardening nickel-chromium alloy that combines the strength of forged steel with the corrosion resistance of nickel-based alloys. First developed in the 1950s, it has since become a widely used material in the aerospace, oil and gas, and chemical industries.
Hastelloy C276, also known as UNS N10276, is a nickel-molybdenum-chromium superalloy renowned for its superior corrosion resistance in a wide range of corrosive environments. Developed in the 1960s, it has since been used in the most demanding chemical, oil and gas, and marine environments.
Chemical composition comparison between Inconel 718 and Hastelloy C-276
| Element | Hastelloy C-276 (wt%) | Inconel 718 (wt%) |
|---|---|---|
| Nickel (Ni) | Balance | 50.0 - 55.0 |
| Chromium (Cr) | 14.5 - 16.5 | 17.0 - 21.0 |
| Iron (Fe) | 4.0 - 7.0 | Balance (≤21.0) |
| Molybdenum (Mo) | 15.0 - 17.0 | - |
| Tungsten (W) | 3.0 - 4.5 | - |
| Cobalt (Co) | ≤ 2.5 | ≤ 1.0 |
| Manganese (Mn) | ≤ 1.0 | ≤ 0.35 |
| Carbon (C) | ≤ 0.01 | ≤ 0.08 |
| Silicon (Si) | ≤ 0.08 | ≤ 0.35 |
| Phosphorus (P) | ≤ 0.04 | ≤ 0.015 |
| Sulfur (S) | ≤ 0.03 | ≤ 0.015 |
| Vanadium (V) | ≤ 0.35 | - |
| Aluminum (Al) | - | 0.20 - 0.80 |
| Titanium (Ti) | - | 0.65 - 1.15 |
| Niobium (Nb) | - | 4.75 - 5.50 |
| Tantalum (Ta) | - | ≤ 0.05 |
| Copper (Cu) | - | ≤ 0.30 |
Mechanical properties of Hastelloy C-276 and Inconel 718
| Property | Hastelloy C-276 (Typical Room Temp) | Inconel 718 (Typical Room Temp) |
|---|---|---|
| Tensile Strength (Ultimate) | 690 MPa (100 ksi) min | 1241 MPa (180 ksi) min |
| Yield Strength (0.2% Offset) | 283 MPa (41 ksi) min | 1034 MPa (150 ksi) min |
| Elongation (in 2 in / 50 mm) | 40% min | 12% min |
| Hardness | Rb 100 max | Rb 98 - 105 (Annealed), Rc 36 - 44 (Aged) |
| Modulus of Elasticity (Young's) | 205 GPa (29.7 x 10⁶ psi) | 200 GPa (29.0 x 10⁶ psi) |
| Density | 8.89 g/cm³ (0.321 lb/in³) | 8.19 g/cm³ (0.296 lb/in³) |
Inconel 718 and Hastelloy C276 – 2. Key Characteristics
Key characteristics of Inconel 718:
High Strength: Inconel 718 maintains high strength even at high temperatures, making it suitable for demanding structural applications.
Good Corrosion Resistance: This alloy exhibits good corrosion resistance in a variety of environments, including those containing chlorides, sulfides, and oxidizers.
Excellent Machinability: Inconel 718 is easy to weld, braze, and form, making it widely applicable in manufacturing processes.
Low Coefficient of Thermal Expansion: The alloy has a relatively low coefficient of thermal expansion, minimizing thermal stress during high-temperature operation.
Key characteristics of Hastelloy C276:
Excellent Corrosion Resistance: Hastelloy C276 exhibits excellent resistance to chloride-induced stress corrosion cracking, pitting, and crevice corrosion, making it ideal for highly corrosive environments.
High Thermal Stability: This alloy retains its mechanical properties at high temperatures, making it suitable for high-temperature applications. Good machinability: Hastelloy C276 is easy to weld and form, but special care must be taken to maintain its corrosion resistance during welding.
Low magnetic permeability: This alloy has low magnetic permeability, which minimizes the risk of magneto-corrosion in certain environments.
Key Differences Summary
Key Points: Inconel 718 = High-temperature strength; Hastelloy C276 = Excellent corrosion resistance.
Application Environment: Inconel 718 is suitable for structural components subjected to thermal stress; C276 is suitable for highly corrosive media, such as corrosive fluids.
Chemical Composition: C276 has a higher molybdenum content, thus offering advantages in reducing/acidic corrosion.
Gnee Steel is a professional manufacturer of various nickel-based alloys, including Nickel 201, Nickel 202, Hastelloy C-276, Hastelloy C-22, Hastelloy B, Hastelloy C-4, Inconel Alloy 600, Inconel 625, Inconel 718, Inconel X-750, Incoloy Alloy 800, Incoloy 800H/HT, Incoloy 825, Monel Alloy 400, Monel K500, and high-temperature alloys. We specialize in the production and sales of alloy materials. Gnee Steel's products are widely used in aerospace, chemical, power, automotive, and nuclear energy industries, and we can provide customized alloy material solutions according to customer needs. For alloy material price inquiries or to request customized alloy material solutions, please feel free to contact us at ru@gneesteelgroup.com for a quote.