Invar 36,Nilo 36 Pipe,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 Pipe (UNS K93601) - Product Introduction** #### **Overview** **Invar 36**, commercially known as **Nilo 36 Pipe** (UNS K93601), represents the tubular form of the classic 36% nickel-iron low expansion alloy. This product is specifically engineered for applications requiring hollow structural components with exceptional dimensional stability across temperature variations. The pipe form provides optimal strength-to-weight ratio while maintaining the characteristic low thermal expansion properties that make Invar alloys unique in demanding thermal environments. #### **Key Characteristics** * **Ultra-Low Thermal Expansion:** CTE typically **1.6 × 10⁻⁶/°C** (20-100°C) * **Excellent Pressure Integrity:** Suitable for high-pressure and vacuum applications * **Superior Dimensional Stability:** Maintains precise dimensions under thermal cycling * **Good Corrosion Resistance:** Comparable to low-alloy steels * **Excellent Fabrication Properties:** Weldable and formable using standard methods --- #### **1. Chemical Composition** | Element | Content (%) | |---------|-------------| | **Nickel (Ni)** | 35.0 - 37.0 | | **Iron (Fe)** | Balance | | **Carbon (C)** | 0.10 max | | **Manganese (Mn)** | 0.50 max | | **Silicon (Si)** | 0.30 max | | **Phosphorus (P)** | 0.025 max | | **Sulfur (S)** | 0.025 max | | **Cobalt (Co)** | 0.50 max | | **Chromium (Cr)** | 0.25 max | --- #### **2. Physical Properties** | Property | Value | |----------|-------| | **Density** | 8.13 g/cm³ (0.294 lb/in³) | | **Melting Point** | 1425°C (2600°F) | | **Mean Coefficient of Thermal Expansion** | **1.6 × 10⁻⁶/°C** (20-100°C) | | **Thermal Conductivity** | 10.5 W/m·K (71 BTU·in/hr·ft²·°F) | | **Specific Heat Capacity** | 515 J/kg·K (0.123 BTU/lb·°F) | | **Modulus of Elasticity** | 145 GPa (21 × 10⁶ psi) | | **Electrical Resistivity** | 0.75 μΩ·m | --- #### **3. Mechanical Properties** | Property | Seamless Pipe | Welded Pipe | |----------|---------------|-------------| | **Tensile Strength** | 480-550 MPa | 450-520 MPa | | **Yield Strength (0.2% Offset)** | 280-350 MPa | 260-320 MPa | | **Elongation** | 30-40% | 25-35% | | **Hardness** | 75-85 HRB | 70-80 HRB | --- #### **4. Standard Specifications & Sizes** **Available Forms:** * **Seamless Pipe:** Highest integrity for pressure applications * **Welded Pipe:** Economical alternative for structural applications * **Schedule:** SCH 10, SCH 20, SCH 40, SCH 80 * **Size Range:** 1/8" to 12" NB (Nominal Bore) **Standard Dimensions:** * **Wall Thickness:** 1.0 mm to 20 mm * **Lengths:** Standard 3-6 meters, cut-to-length available * **Tolerances:** Per ASTM A530/A530M --- #### **5. Product Applications** **Aerospace & Defense:** * **Satellite Fuel Lines:** Propellant management systems * **Cryogenic Transfer Lines:** For spacecraft thermal control systems * **Aircraft Hydraulic Lines:** High-stability fluid conveyance * **Radar Cooling Systems:** Precision coolant pathways **Semiconductor Industry:** * **Ultra-Pure Gas Delivery:** For wafer processing equipment * **Vacuum Chamber Components:** Structural and gas feed elements * **Thermal Management Systems:** Heat transfer applications * **Chemical Distribution:** High-purity chemical delivery **Energy Sector:** * **LNG Transfer Lines:** Cryogenic fluid handling * **Solar Thermal Systems:** Heat transfer conduits * **Nuclear Instrumentation:** Sensor conduits and protection tubes * **Geothermal Systems:** High-temperature fluid handling **Scientific Research:** * **Particle Accelerator Components:** Beam line components * **Cryogenic Research Equipment:** Liquid gas transfer systems * **Telescope Cooling Systems:** Thermal management components * **Laboratory Instrumentation:** Precision fluid handling systems --- #### **6. International Standards** | Standard Organization | Standard Number | Title / Scope | |----------------------|-----------------|---------------| | **ASTM** | ASTM F1684 | Standard Specification for Pipe and Tube | | **ASME** | SA-658 | Boiler and Pressure Vessel Code Specification | | **AMS** | AMS 7725 | Aerospace Material Specification | | **DIN** | DIN 1.3912 | German Standard for Pipe Products | | **EN** | EN 1.3912 | European Standard | | **JIS** | JIS NCF 2 | Japanese Industrial Standard | --- #### **7. Fabrication & Installation** **Welding Procedures:** * **Processes:** GTAW (TIG) preferred, GMAW (MIG) acceptable * **Filler Metal:** AWS A5.14 ERNiFeCr or matching composition * **Preheat:** Not typically required * **Post-Weld Heat Treatment:** Recommended at 425-540°C **Machining & Forming:** * **Cutting:** Band saws or abrasive cutting recommended * **Bending:** Cold bending with appropriate bend radii * **Threading:** Standard pipe threading methods applicable * **Flaring/Flanging:** Possible with proper tooling **Testing & Inspection:** * **Non-Destructive Testing:** UT, RT, PT, MT as required * **Pressure Testing:** Hydrostatic or pneumatic per application * **Dimensional Inspection:** Per specified tolerances * **Material Certification:** 3.1 Mill Certificate provided --- #### **8. Design Considerations** **Thermal Performance:** * Minimum thermal expansion reduces stress in fixed systems * Suitable for temperature ranges from cryogenic to 400°C * Maintains dimensional stability during thermal cycling **Structural Considerations:** * Excellent fatigue resistance * Good creep resistance at elevated temperatures * Maintains strength at cryogenic temperatures **Corrosion Resistance:** * Resists atmospheric corrosion * Suitable for mild chemical environments * Not recommended for highly corrosive media without protection --- #### **Conclusion** Nilo 36 Pipe (UNS K93601) provides an exceptional combination of low thermal expansion, structural integrity, and fabrication versatility for tubular applications. Its unique properties make it particularly valuable in aerospace, semiconductor, and energy applications where dimensional stability under thermal cycling is critical. The availability in both seamless and welded forms, along with comprehensive international standard coverage, ensures that engineers can specify this material with confidence for the most demanding applications. Proper fabrication techniques and adherence to recommended welding procedures are essential to maintain the material's unique properties in the final installation.

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 2407 gallon liquid totes Special package is available on request.