Hastelloy S / UNS N06635: Properties, Applications, and Features
✅ General Technical Characteristics
Hastelloy S (UNS N06635) is a high-temperature nickel-based alloy specifically designed for extreme thermal environments. It offers exceptional resistance to oxidation and carbide formation during prolonged exposure to high temperatures. The high content of nickel, molybdenum, and chromium provides excellent strength, thermal stability, and corrosion resistance in aggressive environments.
Main Characteristics:
- High thermal stability at temperatures up to 1093°C.
- Excellent resistance to oxidation and corrosion in aggressive environments.
- High creep strength and resistance to deformation under prolonged heating.
- Superior weldability and machinability.
- Increased resistance to carbide and oxide formation during prolonged heating.
🔬 Chemical Composition of Hastelloy S / UNS N06635 (%):
- Nickel (Ni): 55.0 – 61.0
- Chromium (Cr): 14.0 – 17.0
- Molybdenum (Mo): 6.0 – 8.0
- Iron (Fe): ≤ 3.0
- Cobalt (Co): ≤ 3.0
- Silicon (Si): ≤ 0.20
- Manganese (Mn): ≤ 1.0
- Carbon (C): ≤ 0.05
- Phosphorus (P): ≤ 0.03
- Sulfur (S): ≤ 0.03
💡 The combination of nickel, chromium, and molybdenum ensures outstanding resistance to high temperatures and harsh operating conditions.
🏭 Applications
Due to its unique properties, Hastelloy S is widely used in various industries requiring high resistance to thermal stress and corrosion.
Main Application Areas:
- Aerospace and aviation industries (turbine components, exhaust systems, heat-resistant structures).
- Chemical and petrochemical industries (reactors, heat exchangers, pipelines).
- Energy sector (steam and gas turbine components, boiler equipment).
- Metallurgy (thermal processing equipment, furnaces, heat-resistant containers).
- Medical and laboratory equipment manufacturing.
📊 Mechanical Properties
- Tensile Strength (Rm): 900 – 1100 MPa
- Yield Strength (Rp0.2): ≥ 400 MPa
- Hardness (HB): 230 – 280 HB
- Elongation (A5): ≥ 30 %
⭐ Features
- High heat resistance – maintains mechanical properties at temperatures exceeding 1000°C.
- Corrosion resistance – withstands aggressive acids and oxidizing environments.
- Excellent weldability – easily weldable using various methods.
- Minimal carbide formation – prevents material degradation under prolonged heating.
- Strength and durability – endures extreme mechanical and thermal loads.
Hastelloy S Delivery Forms
| Hastelloy S wheel | Diameter 4-300mm |
| Hastelloy S Sheet | Thickness 0.5-20mm |
| Hastelloy S Tape | Thickness 0.2-2mm |
| Stripe Hastelloy S | Thickness 10-50mm |
| Hastelloy S wire | Diameter 0.5-9mm |
| Hastelloy S pipe | – Hot-rolled round pipe with a diameter of 38 to 244.5 mm, thickness from 3mm to 25mm -Cold drawn round tube diameter from 6mm to 219.1mm thickness from 0.9 to 14.2mm |




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