C 800 Nickel-Iron-Chromium Alloy,UNS N08800,E FORU

### **Product Introduction: C-800 Nickel-Iron-Chromium Alloy (UNS N08800)** **C-800 Nickel-Iron-Chromium Alloy (UNS N08800)** is a solution-strengthened nickel-iron-chromium superalloy designed for exceptional performance in high-temperature environments and corrosive conditions. This versatile alloy maintains excellent strength and oxidation resistance at elevated temperatures up to 815°C (1500°F), while offering outstanding resistance to carburization, sulfidation, and chloride stress corrosion cracking. The carefully balanced composition provides optimal stability in both oxidizing and reducing atmospheres, making it particularly valuable for thermal processing, chemical processing, and power generation applications. The alloy's controlled aluminum and titanium content enables the formation of a stable, protective oxide scale that ensures long-term performance in demanding high-temperature service conditions, while its nickel content provides fundamental resistance to chloride-ion stress corrosion cracking. --- #### **1. Chemical Composition (Weight %)** The chemical composition of C-800 Nickel-Iron-Chromium Alloy per UNS N08800 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)** | 0.10 max | | **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 (Annealed Condition):** | Property | Value | |----------|-----------------| | **Tensile Strength** | 520 - 690 MPa | 75 - 100 ksi | | **Yield Strength (0.2% Offset)** | 210 - 345 MPa | 30 - 50 ksi | | **Elongation** | 30 - 50% | | **Hardness (Rockwell B)** | 75 - 85 HRB | **Elevated Temperature Properties (at 650°C/1200°F):** | **Tensile Strength** | 380 MPa | 55 ksi | | **Yield Strength** | 195 MPa | 28 ksi | | **Creep Rupture Strength (1000h)** | 55 MPa | 8 ksi | --- #### **3. Key Characteristics & Product Applications** **Key Characteristics:** - **Excellent High-Temperature Strength**: Maintains mechanical properties at temperatures up to 815°C - **Superior Oxidation Resistance**: Outstanding performance in high-temperature oxidizing atmospheres - **Carburization Resistance**: Excellent 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 - **Good Fabricability**: Excellent weldability and formability characteristics **Product Applications:** C-800 Nickel-Iron-Chromium Alloy serves critical functions in demanding applications: - **Thermal Processing Industry**: - Radiant tubes and furnace muffles - Heat treatment retorts and baskets - Annealing covers and fixtures - Roller hearth furnace components - **Chemical Processing**: - Steam hydrocarbon reformer tubing - Catalyst support grids - High-temperature reactor internals - Process heating elements - **Power Generation**: - Heat recovery steam generators - Superheater and reheater tubing - Nuclear steam generator tubing - Boiler components - **Petrochemical Industry**: - Ethylene furnace components - Pyrolysis tubing - Heat exchanger tubing - Process piping systems --- #### **4. International Standards & Specifications** C-800 Nickel-Iron-Chromium Alloy complies with the following international standards: **Primary Specifications:** - **UNS N08800**: Unified Numbering System - **ASTM B163**: Seamless Condenser and Heat-Exchanger Tubes - **ASTM B164**: Rod and Bar - **ASTM B165**: Seamless Pipe and Tube - **ASTM B166**: Rod, Bar, and Wire - **ASTM B167**: Seamless Pipe and Tube - **ASTM B168**: Plate, Sheet, and Strip **International Equivalents:** - **EN**: 1.4876 (X10NiCrAlTi32-20) - **DIN**: 1.4876 - **JIS**: NCF 800 - **ISO**: 6207 (NW 8800) - **AMS**: 5766, 5872 (Aerospace Material Specifications) --- #### **Summary of Key Advantages** - **Versatile High-Temperature Performance**: Excellent mechanical properties and oxidation resistance up to 815°C - **Superior Environmental Resistance**: Outstanding performance in oxidizing, carburizing, and sulfidizing atmospheres - **Proven Reliability**: Extensive service history in demanding industrial applications - **Excellent Fabricability**: Good weldability and formability for complex component manufacturing - **Broad Chemical Compatibility**: Suitable for various corrosive and high-temperature environments - **Comprehensive Standardization**: Meets international quality and performance standards **Technical Note**: C-800 Nickel-Iron-Chromium Alloy exhibits excellent weldability using matching filler metals and conventional welding processes including GTAW, GMAW, and SMAW. The alloy's aluminum and titanium content promotes the formation of a protective, adherent oxide scale that provides long-term oxidation resistance. For optimal high-temperature performance, a solution annealing treatment at 980-1150°C (1800-2100°F) followed by rapid cooling is recommended. The material demonstrates excellent resistance to chloride stress corrosion cracking and maintains good mechanical properties after prolonged exposure to high temperatures. Proper cleaning and handling procedures should be maintained to ensure optimal performance in critical applications. The alloy is particularly noted for its stability in cyclic temperature service and resistance to oxidation in high-temperature steam environments.

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 3191 gallon liquid totes Special package is available on request.