825 Nickel Chromium Resistance Wire,75Ni20Cr2.5Fe2.5AI Alloy,E FORU

### **Product Introduction: 825 Nickel-Chromium Resistance Wire (75Ni20Cr2.5Fe2.5Al Alloy)** **825 Nickel-Chromium Resistance Wire** is a high-performance nickel-chromium-iron-aluminum resistance alloy composed of approximately 75% nickel, 20% chromium, 2.5% iron, and 2.5% aluminum. This advanced resistance alloy is specifically engineered to provide exceptional high-temperature performance, superior oxidation resistance, and enhanced mechanical strength through the strategic addition of aluminum and controlled iron content to the traditional nickel-chromium system. The unique composition of this alloy offers improved high-temperature stability and extended service life, making it particularly suitable for demanding applications where conventional nickel-chromium alloys may not provide adequate long-term performance or reliability. --- #### **1. Chemical Composition (Weight %)** The typical chemical composition of 825 Nickel-Chromium Resistance Wire is as follows: | Element | Content (%) | Element | Content (%) | |---------|-------------|---------|-------------| | **Nickel (Ni)** | 73.0 - 77.0 | **Chromium (Cr)** | 19.0 - 21.0 | | **Aluminum (Al)** | 2.3 - 2.8 | **Iron (Fe)** | 2.3 - 2.8 | | **Manganese (Mn)** | 0.5 - 1.5 | **Silicon (Si)** | 0.5 - 1.5 | | **Carbon (C)** | 0.08 max | **Copper (Cu)** | 0.25 max | | **Sulfur (S)** | 0.01 max | **Phosphorus (P)** | 0.02 max | | **Other Elements** | 0.30 max | | | --- #### **2. Physical & Mechanical Properties** **Physical Properties:** | Property | Metric Units | Imperial Units | |----------|-----------------|------| | **Density** | 8.32 g/cm³ | 0.301 lb/in³ | | **Melting Point** | 1390 °C | 2534 °F | | **Maximum Operating Temperature** | 1250 °C | 2282 °F | | **Thermal Conductivity** | 13.8 W/m·K | 95.7 Btu·in/hr·ft²·°F | | **Coefficient of Thermal Expansion** | 13.9 μm/m·°C | 7.7 μin/in·°F | | **Specific Heat** | 455 J/kg·K | 0.109 Btu/lb·°F | | **Electrical Resistivity** | 1.15 μΩ·m | 690 Ω·cir mil/ft | **Mechanical Properties:** | Property | Value | |----------|-----------------| | **Tensile Strength** | 800-950 MPa | 116-138 ksi | | **Yield Strength (0.2% Offset)** | 450-600 MPa | 65-87 ksi | | **Elongation** | 20-30% | | **Hardness (Rockwell B)** | 90-100 HRB | | **Temperature Coefficient of Resistance** | 0.00009 °C⁻¹ | --- #### **3. Key Characteristics & Product Applications** **Key Characteristics:** - **Exceptional High-Temperature Strength**: Aluminum addition significantly enhances mechanical properties at elevated temperatures - **Superior Oxidation Resistance**: Forms a protective Al-Cr-Fe oxide scale for maximum service life - **Excellent Thermal Stability**: Maintains dimensional stability under severe thermal cycling conditions - **Enhanced Creep Resistance**: Superior resistance to deformation under load at high temperatures - **Good Electrical Characteristics**: Stable resistivity with minimal temperature dependence - **Excellent Fabricability**: Suitable for complex forming and winding operations **Product Applications:** 825 Nickel-Chromium Resistance Wire serves critical functions in demanding high-temperature applications: - **Advanced Industrial Heating Systems**: - High-temperature industrial furnace elements - Heat treatment furnace components - Specialized processing equipment - High-performance ceramic kilns - **Precision Electrical Components**: - High-stability power resistors - Precision heating elements - Critical control system heaters - High-reliability resistance standards - **High-Temperature Technology Applications**: - Aerospace heating systems - Semiconductor manufacturing equipment - Research and development furnaces - Advanced materials processing - **Specialized Industrial Applications**: - Glass manufacturing equipment - Metal processing furnaces - High-temperature sensors - Specialized thermal systems --- #### **4. International Standards & Specifications** 825 Nickel-Chromium Resistance Wire complies with major international standards: **International Standards:** - **ASTM B267**: Standard Specification for Wire for Use in Wire-Wound Resistors - **IEC 60115**: Fixed resistors for use in electronic equipment - **DIN 17470**: Resistance alloys for electrical heating - **JIS C 2520**: Resistance alloys for electrical purposes **Industry Specifications:** - **UL 758**: Appliance Wiring Material Standard - **RoHS Compliance**: Meets environmental requirements - **ISO 9001**: Quality management systems --- #### **Summary of Key Advantages** - **Premium High-Temperature Performance**: Reliable operation up to 1250°C - **Enhanced Oxidation Resistance**: Aluminum-chromium-iron oxide scale provides superior protection - **Excellent Mechanical Properties**: High strength and stability at elevated temperatures - **Superior Thermal Stability**: Minimal resistance drift under thermal cycling - **Extended Service Life**: Longer operational life in demanding applications - **Proven Reliability**: Consistent performance in critical applications **Technical Note**: The strategic combination of aluminum and iron in 825 Nickel-Chromium Resistance Wire promotes the formation of a dense, highly protective oxide scale that provides exceptional resistance to high-temperature oxidation and degradation. The alloy demonstrates excellent stability under cyclic heating conditions and maintains consistent electrical characteristics throughout its service life. Proper manufacturing processes and heat treatments are essential to optimize the alloy's properties. For heating element applications, appropriate design considerations should include proper support systems to accommodate thermal expansion and prevent mechanical stress concentrations. Storage in clean, dry conditions is recommended to maintain surface quality and prevent contamination that could affect high-temperature performance. Regular maintenance and adherence to recommended operating parameters significantly enhance the service life and reliability of components manufactured from this advanced resistance alloy.

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 3178 gallon liquid totes Special package is available on request.