C 800H Nickel-Iron-Chromium Alloy,UNS N08810,E FORU

### **Product Introduction: C-800H Nickel-Iron-Chromium Alloy (UNS N08810)** **C-800H Nickel-Iron-Chromium Alloy (UNS N08810)** is an optimized version of the C-800 alloy with controlled carbon content and specific thermal processing to enhance high-temperature strength and structural stability. This solution-strengthened nickel-iron-chromium superalloy is specifically designed for applications requiring superior creep and rupture properties at elevated temperatures up to 815°C (1500°F). The "H" designation indicates enhanced high-temperature performance achieved through precise chemistry control and specialized heat treatment. The alloy offers exceptional resistance to oxidation, carburization, and sulfidation while maintaining excellent mechanical properties under prolonged exposure to high temperatures, making it particularly suitable for petrochemical processing, heat treatment equipment, and power generation applications. --- #### **1. Chemical Composition (Weight %)** The chemical composition of C-800H Nickel-Iron-Chromium Alloy per UNS N08810 is as follows: | Element | Content (%) | Element | Content (%) | |---------|-------------|---------|-------------| | **Nickel (Ni)** | 30.0 - 35.0 | **Chromium (Cr)** | 19.0 - 23.0 | | **Iron (Fe)** | 39.5 min | **Aluminum (Al)** | 0.15 - 0.60 | | **Titanium (Ti)** | 0.15 - 0.60 | **Carbon (C)** | 0.06 - 0.10 | | **Manganese (Mn)** | 1.50 max | **Silicon (Si)** | 1.00 max | | **Copper (Cu)** | 0.75 max | **Sulfur (S)** | 0.015 max | --- #### **2. Physical & Mechanical Properties** **Physical Properties:** | Property | Metric Units | Imperial Units | |----------|-----------------|------| | **Density** | 8.00 g/cm³ | 0.289 lb/in³ | | **Melting Range** | 1350 - 1400 °C | 2460 - 2550 °F | | **Thermal Conductivity** | 11.7 W/m·K | 81.1 Btu·in/hr·ft²·°F | | **Coefficient of Thermal Expansion** | 14.2 μm/m·°C | 7.9 μin/in·°F | | **Specific Heat** | 460 J/kg·K | 0.110 Btu/lb·°F | | **Electrical Resistivity** | 0.99 μΩ·m | - | | **Modulus of Elasticity** | 200 GPa | 29.0 x 10⁶ psi | **Mechanical Properties (Solution Annealed Condition):** | Property | Value | |----------|-----------------| | **Tensile Strength** | 586 - 758 MPa | 85 - 110 ksi | | **Yield Strength (0.2% Offset)** | 241 - 414 MPa | 35 - 60 ksi | | **Elongation** | 30 - 50% | | **Hardness (Rockwell B)** | 75 - 85 HRB | **Elevated Temperature Properties (at 650°C/1200°F):** | **Tensile Strength** | 400 MPa | 58 ksi | | **Yield Strength** | 210 MPa | 30 ksi | | **Creep Rupture Strength (1000h)** | 70 MPa | 10 ksi | --- #### **3. Key Characteristics & Product Applications** **Key Characteristics:** - **Enhanced High-Temperature Strength**: Optimized creep and rupture properties at elevated temperatures - **Superior Oxidation Resistance**: Excellent performance in high-temperature oxidizing atmospheres - **Carburization Resistance**: Outstanding resistance to carbon penetration in carburizing environments - **Sulfidation Resistance**: Good performance in sulfur-containing atmospheres - **Chloride Stress Corrosion Cracking Resistance**: Excellent resistance to chloride-induced SCC - **Controlled Microstructure**: Optimized grain size and precipitation for high-temperature service **Product Applications:** C-800H Nickel-Iron-Chromium Alloy serves critical functions in demanding high-temperature applications: - **Petrochemical Industry**: - Ethylene cracking furnace tubes - Steam methane reformer tubing - Pyrolysis heater components - Process heater tubing - **Thermal Processing**: - Radiant tubes and charge baskets - Heat treatment retorts and fixtures - Annealing furnace components - Roller hearth furnace rolls - **Power Generation**: - Heat recovery steam generator tubing - Superheater and reheater components - Nuclear steam generator tubing - High-temperature heat exchangers - **Chemical Processing**: - Catalyst support systems - High-temperature reactor internals - Process heating elements - Reformers and crackers --- #### **4. International Standards & Specifications** C-800H Nickel-Iron-Chromium Alloy complies with the following international standards: **Primary Specifications:** - **UNS N08810**: Unified Numbering System - **ASTM B407**: Seamless Pipe and Tube - **ASTM B408**: Rod and Bar - **ASTM B409**: Plate, Sheet, and Strip - **ASTM B564**: Forgings **International Equivalents:** - **EN**: 1.4958 (X5NiCrAlTi31-20) - **DIN**: 1.4958 - **JIS**: NCF 800H - **ISO**: 6207 (NW 8810) - **AMS**: 5767, 5873 (Aerospace Material Specifications) --- #### **Summary of Key Advantages** - **Optimized High-Temperature Performance**: Enhanced creep and rupture strength for elevated temperature service - **Superior Environmental Resistance**: Excellent oxidation, carburization, and sulfidation resistance - **Controlled Chemistry**: Precise carbon content and thermal processing for consistent performance - **Proven Reliability**: Extensive service history in demanding petrochemical and power applications - **Excellent Fabricability**: Good weldability and formability for complex component manufacturing - **Comprehensive Standardization**: Meets international quality and performance standards **Technical Note**: C-800H requires specific heat treatment to achieve optimal high-temperature properties, typically involving solution annealing at 1149°C (2100°F) minimum to ensure adequate grain growth and carbide solution. The controlled carbon content (0.06-0.10%) and specific thermal processing differentiate it from standard C-800, providing enhanced creep rupture strength and microstructural stability. The alloy exhibits excellent weldability using matching filler metals and conventional welding processes. For optimal performance in high-temperature service, proper solution annealing and thermal stabilization treatments are essential. The material demonstrates superior resistance to oxidation in high-temperature steam environments and maintains excellent mechanical properties under prolonged exposure to elevated temperatures.

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 3192 gallon liquid totes Special package is available on request.