INCOLOY alloy 803 Fe-Ni-Cr Alloy,UNS S35045; 1

### **Product Introduction: INCOLOY® Alloy 803 (UNS S35045)** **INCOLOY® Alloy 803** is an iron-nickel-chromium austenitic alloy specifically developed for high-temperature applications requiring exceptional resistance to carburization, sulfidation, and oxidation. This advanced alloy offers improved microstructural stability and superior high-temperature strength compared to conventional heat-resistant alloys, making it particularly suitable for severe service conditions in petrochemical processing, thermal reforming, and ethylene production applications. The alloy's optimized composition provides an excellent balance of creep strength, thermal stability, and environmental resistance, ensuring reliable long-term performance in aggressive high-temperature environments up to 1150°C (2100°F). --- ### **Chemical Composition** | Element | Content (%) | |---------|-------------| | **Iron (Fe)** | Balance | | **Nickel (Ni)** | 32.0 - 37.0 | | **Chromium (Cr)** | 25.0 - 29.0 | | **Manganese (Mn)** | 1.5 max | | **Silicon (Si)** | 0.75 - 1.50 | | **Aluminum (Al)** | 0.15 - 0.60 | | **Carbon (C)** | 0.08 - 0.15 | | **Copper (Cu)** | 0.75 max | | **Nitrogen (N)** | 0.15 - 0.25 | | **Phosphorus (P)** | 0.030 max | | **Sulfur (S)** | 0.015 max | --- ### **Physical Properties** | Property | Value | |----------|-------| | **Density** | 7.94 g/cm³ | | **Melting Point** | 1370 - 1420 °C | | **Thermal Conductivity** | 13.5 W/m·K (at 20°C) | | **Electrical Resistivity** | 1.05 μΩ·m | | **Modulus of Elasticity** | 200 GPa | | **Coefficient of Thermal Expansion** | 15.5 μm/m·°C (20-1000°C) | | **Specific Heat Capacity** | 500 J/kg·K | | **Magnetic Response** | Essentially non-magnetic | --- ### **Mechanical Properties** **Room Temperature Properties:** - **Tensile Strength:** 620 - 860 MPa - **Yield Strength (0.2% Offset):** 310 - 480 MPa - **Elongation:** 35 - 45% - **Hardness:** 85 - 100 HRB **High-Temperature Performance:** - **Creep Rupture Strength (1000°C/1000h):** 20 MPa - **Tensile Strength at 870°C:** 180 MPa - **Yield Strength at 870°C:** 120 MPa - **Excellent thermal fatigue resistance** --- ### **Heat Treatment** **Standard Heat Treatment:** - **Solution Annealing:** 1150 - 1200°C (2100 - 2200°F) - **Soaking Time:** 30-60 minutes per inch thickness - **Cooling:** Rapid water quenching or air cooling **Stress Relieving:** - **Temperature:** 870 - 900°C (1600 - 1650°F) - **Cooling:** Controlled cooling rate --- ### **Key Characteristics & Advantages** 1. **Exceptional High-Temperature Resistance** - Superior resistance to carburization and metal dusting - Excellent oxidation resistance up to 1150°C - Good sulfidation resistance in sulfur-containing environments 2. **Enhanced Microstructural Stability** - Controlled precipitation behavior - Resistance to sigma phase formation - Stable mechanical properties during long-term exposure 3. **Optimized Mechanical Properties** - Good creep and stress rupture strength - Excellent thermal fatigue resistance - Adequate ductility and toughness 4. **Excellent Fabricability** - Good weldability using conventional methods - Suitable for hot and cold working operations - Can be machined using standard techniques --- ### **Product Applications** **Petrochemical Industry:** - Ethylene cracking furnace tubes - Thermal reformer components - Pyrolysis coil assemblies - Process heater tubes **Chemical Processing:** - High-temperature reactors - Heat exchanger tubing - Process piping systems - Catalyst support grids **Power Generation:** - Boiler components - Heat recovery systems - Superheater tubes - Power plant tubing **Industrial Heating:** - Radiant tubes - Heat treatment fixtures - Industrial furnace components - Annealing equipment --- ### **International Standards** | Standard Type | Standard Number | Product Form | |---------------|-----------------|--------------| | **UNS** | S35045 | Unified Numbering System | | **ASTM** | A240 | Plate, Sheet, and Strip | | **ASTM** | A480 | General Requirements for Flat Products | | **ASME** | 2304 | Code Case | | **ASTM** | A213 | Seamless Ferritic and Austenitic Alloy-Steel Boiler Tubes | | **ASTM** | SA249 | Welded Austenitic Steel Boiler Tubes | | **ASTM** | A182 | Forged or Rolled Alloy-Steel Pipe Flanges, Forged Fittings, and Valves and Parts | --- ### **Summary** **INCOLOY® Alloy 803 (UNS S35045)** represents a significant advancement in iron-nickel-chromium alloy technology, specifically engineered to withstand the most severe high-temperature corrosive environments encountered in petrochemical processing and thermal reforming applications. Its optimized composition delivers exceptional resistance to carburization, sulfidation, and oxidation while maintaining excellent mechanical properties and microstructural stability at temperatures up to 1150°C. The alloy's superior performance characteristics, combined with good fabricability and weldability, make it an ideal choice for critical components in ethylene production, chemical processing, and power generation industries. Comprehensive certification to major international standards including ASTM A240, A213, SA249, and ASME 2304 ensures consistent quality and reliability, providing engineers with a proven material solution for demanding high-temperature applications where conventional materials would rapidly degrade. The alloy's balanced properties establish it as a preferred material for advancing efficiency and reliability in high-temperature industrial processes.

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 3352 gallon liquid totes Special package is available on request.