Alloy S,Hastelloy S ,UNS N06635,E FORU

British Specs:，American Specs: AMS 5711 Bar and Forging AMS 5838 Welding Wire AMS 5873 Sheet, Strip and Plate，German Specs:

### **Technical Datasheet: Alloy S (UNS N06635)** **Overview** Alloy S, commercially known as Hastelloy® S and standardized as UNS N06635, is a nickel-chromium-molybdenum wrought superalloy specifically designed for exceptional high-temperature strength and outstanding resistance to oxidizing, sulfidizing, and carburizing environments. Its key differentiator is an optimal balance of microstructural stability, ductility, and thermal fatigue resistance at temperatures up to 1200°C (2200°F), making it superior to many other alloys in cyclic heating and cooling applications. **Key Characteristics** * **Exceptional Thermal Stability:** Resists the formation of detrimental topologically close-packed (TCP) phases and embrittling precipitates after long-term exposure at high temperatures. * **Superior Oxidation Resistance:** Forms a dense, adherent chromia (Cr₂O₃) scale that protects the base metal from further degradation. * **Resistance to Dynamic Gas Environments:** Performs well in fluctuating atmospheres, resisting breakaway oxidation, sulfidation, and carburization. * **Excellent Thermal Fatigue Resistance:** High ductility and strength retention prevent crack initiation and propagation under thermal cycling conditions. --- ### **Chemical Composition (Weight % Typical)** The composition of Alloy S is carefully balanced to provide high-temperature stability without sacrificing fabricability. | Element | Percentage (%) | Primary Function | | :--- | :--- | :--- | | **Nickel (Ni)** | Balance (~67%) | Base element; provides the austenitic matrix and general stability. | | **Chromium (Cr)** | 14.0 - 16.0% | Imparts primary resistance to oxidation and sulfidation. | | **Molybdenum (Mo)** | 14.0 - 16.0% | Provides solid solution strengthening and resistance to reducing acids. | | **Iron (Fe)** | 3.0% max | Residual element, kept low to enhance stability. | | **Tungsten (W)** | 1.0% max | Contributes to solid solution strengthening. | | **Cobalt (Co)** | 2.0% max | Controlled residual element. | | **Manganese (Mn)** | 0.50% max | Aids in hot workability. | | **Silicon (Si)** | 0.40% max | Enhances oxidation resistance; content is controlled. | | **Lanthanum (La)** | 0.02% min | **Key addition:** dramatically improves the spallation resistance of the oxide scale under thermal cycling. | | **Carbon (C)** | 0.015% max | Kept very low to prevent chromium carbide precipitation and enhance stability. | | **Boron (B)** | 0.010% max | Improves creep ductility. | *Note: "Hastelloy" is a registered trademark of Haynes International Inc. The low carbon and addition of lanthanum are critical design features.* --- ### **Physical Properties (Typical)** | Property | Value | | :--- | :--- | | **Density** | 8.86 g/cm³ (0.320 lb/in³) | | **Melting Point** | 1335 - 1380°C (2435 - 2520°F) | | **Specific Heat (20°C)** | 427 J/kg·K | | **Thermal Conductivity** | 11.0 W/m·K (at 20°C) | | **Coefficient of Thermal Expansion** | 12.8 μm/m·°C (20-100°C) | | **Electrical Resistivity** | 1.30 μΩ·m | | **Modulus of Elasticity (Tensile)** | 211 GPa (30.6 x 10⁶ psi) | --- ### **Mechanical Properties (Typical)** **Room Temperature (Annealed Condition):** * **Tensile Strength:** 795 MPa (115 ksi) min * **Yield Strength (0.2% Offset):** 345 MPa (50 ksi) min * **Elongation (in 2 inches / 50 mm):** 35% min **Elevated Temperature (980°C / 1800°F):** * **Tensile Strength:** ~125 MPa (~18 ksi) * **0.2% Yield Strength:** ~85 MPa (~12 ksi) * **Creep-Rupture Strength:** Exhibits excellent long-term stress rupture life and ductility at high temperatures compared to many other chromia-forming alloys. --- ### **Product Applications** Alloy S is primarily used in applications demanding long-term exposure to extreme heat and aggressive environments, particularly where thermal cycling is a factor. * **Industrial Furnaces & Heat Treatment:** * Muffles, retorts, radiant tubes, and furnace rollers. * Baskets and fixtures for carburizing, nitriding, and sintering. * **Aerospace & Gas Turbines:** * Combustion cans, transition ducts, and afterburner components. * Turbine seals and ring segments. * **Chemical & Petrochemical Processing:** * Components in catalytic reforming systems, pyrolysis furnaces, and waste incineration systems. * Hardware exposed to catalyst regeneration environments (cyclic oxidation/sulfidation). * **Glass Manufacturing:** * Support hooks, mandrels, and processing equipment exposed to high temperatures and corrosive fumes. --- ### **International Standards** Alloy S / UNS N06635 is covered by several key international standards. | Standard Organization | Standard Number | Title / Description | | :--- | :--- | :--- | | **ASTM International** | **ASTM B335** | Standard Specification for *Nickel-Molybdenum Alloy Rod and Bar* (A common specification for bar and rod forms). | | **ASTM International** | **ASTM B336** | Standard Specification for *Nickel-Molybdenum Alloy Pipe and Tube* | | **ASTM International** | **ASTM B572** | Standard Specification for *UNS N06635 Rod* (A specific specification for this alloy). | | **ASME (American Society of Mechanical Engineers)** | **ASME SB-335**
**ASME SB-336**
**ASME SB-572** | Equivalent to ASTM standards for code-approved construction of pressure vessels and nuclear components. | | **SAE International** | **AMS 5772** | Aerospace Material Specification for *Bars, Forgings, and Rings, Corrosion and Heat-Resistant, Nickel Alloy 66Cr-15Mo-2W (UNS N06635) Consumable Electrode or Vacuum Induction Melted, Annealed*. | | **SAE International** | **AMS 5790** | Aerospace Material Specification for *Sheet, Strip, and Plate, Corrosion and Heat-Resistant, Nickel Alloy 66Cr-15Mo-2W (UNS N06635) Consumable Electrode or Vacuum Induction Melted, Solution Heat Treated*. | | **UNS (Unified Numbering System)** | **UNS N06635** | The universal designation for this alloy composition. | | **ISO (International Organization for Standardization)** | **(Under Ni-base alloy group)** | Often specified by chemical and mechanical requirements per customer print. | --- **Disclaimer:** This information is for reference purposes only. Material properties can vary based on product form, heat treatment, and manufacturing process. For critical applications, always consult the relevant material standard and the manufacturer's certified test reports. "Hastelloy" is a registered trademark of Haynes International.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 2885 gallon liquid totes Special package is available on request.