Alloy 333,RA-33,UNS N06333，EFORU

### **Alloy 333 / RA-333® (UNS N06333) - Technical Datasheet** --- #### **1. Overview** **Alloy 333**, also known as **RA-333®**, is a nickel-chromium-based superalloy specifically engineered for exceptional high-temperature strength and outstanding resistance to oxidation, carburization, and sulfur-bearing atmospheres. This versatile alloy maintains excellent mechanical properties and corrosion resistance at temperatures up to 1200°C (2200°F), making it particularly suitable for severe thermal processing applications. --- #### **2. Chemical Composition (Weight %)** The composition is carefully balanced for multi-environment high-temperature performance. | Element | Content (%) | Role & Benefit | |---------|-------------|----------------| | **Nickel (Ni)** | Balance | Provides austenitic matrix and high-temperature strength | | **Chromium (Cr)** | 24.0 - 27.0 | Confers oxidation and sulfur resistance | | **Iron (Fe)** | 15.0 - 19.0 | Cost-effective strengthening element | | **Molybdenum (Mo)** | 2.5 - 4.0 | Enhances strength and corrosion resistance | | **Cobalt (Co)** | 2.5 - 4.0 | Improves high-temperature strength | | **Tungsten (W)** | 2.0 - 4.0 | Solid solution strengthening | | **Manganese (Mn)** | 1.5 - 2.5 | Sulfur control and hot workability | | **Silicon (Si)** | 0.5 - 1.5 | Enhances oxidation resistance | | **Aluminum (Al)** | ≤ 0.5 | Contributes to oxidation resistance | | **Carbon (C)** | 0.03 - 0.08 | Optimized for strength and stability | | **Phosphorus (P)** | ≤ 0.03 | Controlled impurity | | **Sulfur (S)** | ≤ 0.03 | Controlled impurity | *Note: "RA-333" is a registered trademark of Rolled Alloys* --- #### **3. Physical Properties** The physical properties support extreme high-temperature applications. | Property | Value | |----------|-------| | **Density** | 8.25 g/cm³ (0.298 lb/in³) | | **Melting Point** | 1320-1370°C (2410-2500°F) | | **Specific Heat (20°C)** | 460 J/kg·K | | **Thermal Conductivity** | 11.5 W/m·K (at 20°C) | | **Mean Coefficient of Thermal Expansion** | 14.2 × 10⁻⁶/°C (20-300°C) | | **Electrical Resistivity** | 1.18 μΩ·m | | **Modulus of Elasticity** | 211 GPa (30.6 × 10⁶ psi) | | **Magnetic Permeability** | Essentially non-magnetic | --- #### **4. Mechanical Properties** The alloy maintains excellent strength at elevated temperatures. **Room Temperature (Annealed):** | Property | Value | |----------|-------| | **Tensile Strength** | 690-860 MPa (100-125 ksi) | | **Yield Strength (0.2% Offset)** | 345-485 MPa (50-70 ksi) | | **Elongation** | 40-50% | | **Hardness** | 85-100 HRB | **Elevated Temperature Properties (870°C/1600°F):** | Property | Value | |----------|-------| | **Tensile Strength** | 275 MPa (40 ksi) | | **Yield Strength** | 195 MPa (28 ksi) | | **Creep Rupture Strength (1000h)** | 55 MPa (8 ksi) | --- #### **5. Product Applications** **Alloy 333** serves in severe high-temperature environments across multiple industries: - **Heat Treatment Industry:** - Furnace radiant tubes and retorts - Heat treatment fixtures and baskets - Carburizing and nitriding equipment - Annealing covers and inner covers - **Chemical & Petrochemical:** - Reformers and cracking furnace components - Catalyst support grids - Thermal reactor parts - High-temperature heat exchangers - **Power Generation:** - Gas turbine combustion components - Heat recovery system parts - Boiler components in corrosive environments - Waste incineration system parts - **Industrial Heating:** - Soaking pit covers - Salt pot fixtures - Lead pot components - Glass manufacturing equipment - **Pollution Control:** - Afterburner components - Incinerator parts - Exhaust system components - Flue gas ducting --- #### **6. International Standards** The material conforms to various international specifications: | Standard | Specification | |----------|---------------| | **ASTM** | ASTM B366 - Factory-Made Wrought Fittings
ASTM B435 - Plate, Sheet, and Strip
ASTM B572 - Rod | | **UNS** | UNS N06333 | | **ASME** | SB-435, SB-572 | | **AMS** | AMS 5718 | | **DIN** | DIN 17742 - NiCr25Fe18Mo | | **EN** | EN 10095 - NW 6022 | --- #### **7. Corrosion Resistance** - **Exceptional** oxidation resistance up to 1200°C (2200°F) - **Outstanding** resistance to carburizing atmospheres - **Excellent** performance in sulfidizing environments - **Good** resistance to chlorine-containing atmospheres - **Superior** resistance to thermal cycling - **Excellent** resistance to nitrogen permeation --- #### **8. Fabrication Characteristics** - **Machining:** Similar to other nickel-chromium alloys - **Welding:** Excellent weldability using GTAW with matching filler metal - **Forming:** Good hot and cold working characteristics - **Heat Treatment:** Solution anneal at 1150-1200°C (2100-2190°F) - **Stress Relief:** Recommended after severe forming operations --- #### **9. Special Considerations** - **Multi-Environment Capability:** Performs well in oxidizing, carburizing, and sulfidizing atmospheres - **Temperature Stability:** Maintains properties during long-term high-temperature exposure - **Thermal Cycling:** Excellent resistance to thermal fatigue - **Aging Characteristics:** Resistant to embrittlement from long-term exposure - **Maximum Service Temperature:** 1200°C (2200°F) continuous service --- #### **10. Summary** **Alloy 333 (RA-333® / UNS N06333)** represents a highly versatile nickel-chromium superalloy engineered for severe high-temperature service in multiple corrosive environments. Its balanced composition provides an optimal combination of oxidation, carburization, and sulfidation resistance, making it particularly valuable in heat treatment, chemical processing, and power generation applications. The alloy's ability to maintain mechanical integrity and corrosion resistance at temperatures up to 1200°C, coupled with excellent fabricability and weldability, establishes it as a preferred material for demanding thermal processing equipment. Governed by comprehensive international standards including ASTM B435 and AMS 5718, Alloy 333 continues to deliver reliable performance in the most challenging high-temperature industrial applications.

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 1721 gallon liquid totes Special package is available on request.