Invar 36,Alloy 36 Plate,UNS K93600,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 / Alloy 36 Plate (UNS K93600) - Product Introduction** #### **Overview** Invar 36, also known as Alloy 36 or by its standard designation UNS K93600, is a low-expansion nickel-iron alloy renowned for its exceptionally low coefficient of thermal expansion (CTE) at temperatures ranging from cryogenic levels up to approximately 300°C (570°F). The name "Invar" derives from the word "invariable," highlighting its key property of dimensional stability with temperature changes. It is primarily used in applications where dimensional changes due to thermal fluctuations must be minimized. #### **Key Characteristics** * **Exceptionally Low Thermal Expansion:** The CTE is typically about 1.6 x 10⁻⁶/°C between 20°C and 100°C, which is less than 1/10th that of carbon steel. * **Good Strength and Toughness:** Maintains good mechanical properties across a wide temperature range. * **Excellent Machinability and Fabricability:** Can be machined, welded, and formed using standard methods, though it work-hardens rapidly. * **High Thermal Conductivity:** Aids in heat dissipation. --- #### **1. Chemical Composition** The unique properties of Invar 36 are achieved through a specific chemical composition that balances nickel and iron. | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | 36.0% min | | **Iron (Fe)** | Balance | | **Carbon (C)** | 0.10% max | | **Manganese (Mn)** | 0.60% max | | **Silicon (Si)** | 0.40% max | | **Phosphorus (P)** | 0.025% max | | **Sulfur (S)** | 0.025% max | | **Cobalt (Co)** | 0.50% max | | **Chromium (Cr)** | 0.25% max | *Note: The precise control of the nickel content is critical to maintaining the low expansion characteristics.* --- #### **2. Physical Properties** | Property | Value / Description | | :--- | :--- | | **Density** | 8.11 g/cm³ (0.293 lb/in³) | | **Melting Point** | ~1427°C (2600°F) | | **Thermal Expansion Coefficient (CTE)** | **1.6 x 10⁻⁶/°C** (20-100°C)
2.7 x 10⁻⁶/°C (20-300°C) | | **Thermal Conductivity** | 10.5 W/m·K (at 20°C) | | **Specific Heat** | 515 J/kg·K (at 20°C) | | **Magnetic Properties** | Ferromagnetic (at room temperature)
Becomes non-magnetic (paramagnetic) above its Curie temperature of ~279°C (534°F). | --- #### **3. Mechanical Properties (Typical for Plate)** Properties can vary based on heat treatment and thickness. | Property | Condition: Annealed | | :--- | :--- | | **Tensile Strength** | 517 MPa (75 ksi) | | **Yield Strength (0.2% Offset)** | 276 MPa (40 ksi) | | **Elongation (in 2")** | 30% | | **Hardness (Rockwell B)** | ~75 HRB | | **Modulus of Elasticity** | 141 GPa (20.5 x 10⁶ psi) | --- #### **4. Product Applications** Invar 36 plate is utilized in critical applications where dimensional stability is paramount. * **Aerospace & Aviation:** * Precision instrumentation and laser components. * Composite molding tools for aircraft wings and fuselages, where its low CTE matches that of the carbon fiber composites being cured. * Satellite and space telescope structures to maintain alignment in the extreme temperature variations of space. * **Cryogenics:** * Storage tanks and transfer lines for liquefied natural gas (LNG) at -162°C. * Components in scientific equipment operating at cryogenic temperatures. * **Electronics & Semiconductors:** * Lead frames. * Shadow masks for cathode ray tubes (historically) and critical frames in OLED displays. * Components in photomasks and wafer steppers. * **Energy & Power Generation:** * Components in power turbines and generators where thermal stability is required. * Seals and other components in nuclear reactors. * **Scientific & Precision Instruments:** * Precision scales, measuring tapes, and geodetic wires (e.g., EDM wires). * Fabry-Perot laser cavities and other optical mounts. --- #### **5. International Standards** Invar 36 is covered by a range of international material and specification standards. | Standard Body | Standard Designation | Form / Specification | | :--- | :--- | :--- | | **UNS** | **K93600** | Unified Numbering System | | **ASTM** | **ASTM F1684** | Standard Specification for Iron-Nickel and Cobalt-Nickel Alloy Plate, Sheet, and Strip | | **AMS** | **AMS 7725** | Sheet, Strip, and Plate (Aerospace Material Specification) | | **EN / Euronorm** | **EN 1.3912 / Ni36** | Wrought Steel Products | | **DIN** | **DIN 1.3912 / Ni36** | German Institute for Standardization | | **JIS** | **JIS NCF 2 / NILO 36** | Japanese Industrial Standards | | **GB** | **GB 4J36** | Chinese National Standard | --- #### **Conclusion** Invar 36 (Alloy 36, UNS K93600) plate is an indispensable engineering material for high-precision industries. Its unparalleled combination of low thermal expansion, good strength, and workability makes it the material of choice for applications ranging from the vastness of space to the microscopic world of semiconductor manufacturing. When sourcing Invar 36 plate, it is crucial to ensure it meets the required international standards for chemical composition and mechanical properties to guarantee performance in its intended application.

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 2396 gallon liquid totes Special package is available on request.