Invar 36,Nilo 36 Other/Similar Specs,UNS K93601,E FORU

British Specs:，American Specs: ASTM F1684 MIL-S-16598 Tooling plate ASTM B388 Sheet & strip ASTM B753 K93050 Free-cut Invar，German Specs:WS 1.3912

**Invar 36 / Nilo 36 & Similar Specifications (UNS K93601) - Comprehensive Technical Introduction** **1. Overview** Invar 36, commercially known as Nilo 36 (UNS K93601), belongs to the family of iron-nickel controlled expansion alloys characterized by their exceptionally low coefficient of thermal expansion (CTE) around room temperature. This unique property, known as the "Invar Effect," makes these alloys indispensable in applications requiring dimensional stability across temperature variations. **2. Chemical Composition (%)** | Element | Standard Range | Special Grades | |---------|----------------|----------------| | Nickel (Ni) | 35.0-37.0 | 35.5-36.5 (Precision) | | Iron (Fe) | Balance | Balance | | Carbon (C) | ≤0.10 | ≤0.05 | | Manganese (Mn) | ≤0.50 | ≤0.35 | | Silicon (Si) | ≤0.30 | ≤0.20 | | Phosphorus (P) | ≤0.025 | ≤0.015 | | Sulfur (S) | ≤0.025 | ≤0.015 | | Cobalt (Co) | ≤0.50 | ≤0.20 | | Chromium (Cr) | ≤0.25 | ≤0.15 | **3. Physical Properties** - **Thermal Properties:** - Mean CTE: 1.6 × 10⁻⁶/°C (20-100°C) - Thermal Conductivity: 10.5 W/m·K at 20°C - Specific Heat: 515 J/kg·K - Melting Range: 1420-1430°C - **Electrical & Magnetic:** - Electrical Resistivity: 0.75 μΩ·m - Curie Temperature: 230°C - Magnetic Saturation: 1.5 Tesla - **Mechanical Constants:** - Density: 8.13 g/cm³ - Modulus of Elasticity: 145 GPa - Poisson's Ratio: 0.29 **4. Related Specifications & Equivalents** **International Standards:** - **ASTM:** F1684, A658 - **AMS:** 7724 (Forgings), 7725 (Sheet/Strip/Plate) - **UNS:** K93601 - **EN/DIN:** 1.3912, Ni36 - **JIS:** NCF 2 - **GB:** 4J36 **International Equivalents:** - **Europe:** FeNi36, Ni36 - **Japan:** NILO 36 - **Russia:** 36N - **France:** AFNOR NC36T **5. Specialized Product Forms & Specifications** **Precision Alloy Variants:** - **Low Carbon Grades:** Enhanced weldability and formability - **Vac Melt Grades:** Improved purity for critical applications - **Precision CTE Grades:** Tighter CTE control (±0.5 × 10⁻⁸/°C) **Special Applications:** - **Seamless Tubing:** ASTM B163 equivalent - **Fine Wire:** Down to 0.025mm diameter - **Foil Products:** Thickness from 0.01mm - **Powder Metallurgy:** For MIM applications **6. Mechanical Properties by Product Form** | Product Form | Condition | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | |--------------|-----------|------------------------|----------------------|----------------| | Sheet/Strip | Annealed | 450-520 | 250-310 | 30-40 | | Bar/Rod | Annealed | 480-550 | 280-350 | 30-35 | | Forgings | Annealed | 500-570 | 300-370 | 25-35 | | Wire | Hard Drawn | 620-760 | 550-690 | 8-15 | **7. Advanced Applications** **Precision Instrumentation:** - Laser interferometer components - Atomic force microscope parts - Standard reference materials - Precision gauge blocks **Aerospace & Defense:** - Space telescope structures - Inertial guidance systems - Radar waveguide components - Satellite mounting platforms **Electronics & Semiconductor:** - Microwave package bases - Crystal oscillator mounts - MEMS packaging components - Hybrid circuit substrates **Scientific Research:** - Length standards - Interferometer bases - Cryogenic instrument mounts - Ultra-stable optical platforms **8. Special Processing & Treatments** **Enhanced Thermal Treatments:** - Stabilization Annealing: For maximum dimensional stability - Stress Relief Cycles: Multiple-stage treatments - Cryogenic Processing: Enhanced stability through phase transformation **Surface Treatments:** - Electropolishing: For ultra-clean surfaces - Passivation: Improved corrosion resistance - Special Coatings: Thermal barrier and protective coatings **9. Quality Standards & Certification** **Testing Requirements:** - CTE Verification: Dilatometer testing per ASTM E228 - Ultrasonic Inspection: Per ASTM A388 - Microcleanliness: Per ASTM E45 - Grain Size: Per ASTM E112 **Certification Levels:** - Standard Mill Certs: 2.1/2.2 EN 10204 - Third Party Verification: Independent laboratory testing - Special Process Certs: NADCAP accredited processes **10. Technical Considerations** **Design Limitations:** - Maximum Service Temperature: 400°C (long-term) - Corrosion Resistance: Limited in harsh environments - Magnetic Properties: Ferromagnetic below Curie temperature **Fabrication Notes:** - Machining: Requires positive rake angles, sharp tools - Welding: GTAW preferred with matching filler - Heat Treatment: Critical for dimensional stability - Stress Relief: Essential after severe forming **11. Future Developments** **Advanced Variants:** - Super Invar: Enhanced low expansion characteristics - Low Magnetostriction Grades: For specialized applications - High Temperature Variants: Extended service range - Composite Forms: Reinforced with other materials **Emerging Applications:** - Quantum computing components - Advanced photonic systems - Next-generation lithography - Space exploration systems **12. Conclusion** Invar 36/Nilo 36 (UNS K93601) and its related specifications represent a critical materials solution for applications demanding exceptional dimensional stability. The comprehensive range of international standards and specialized variants ensures that engineers can select the appropriate grade and specification for even the most demanding thermal stability requirements. Continuous development and refinement of these alloys maintain their position as essential materials in precision engineering, aerospace, and advanced technology 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 2414 gallon liquid totes Special package is available on request.