Alloy 725，Inconel 725 Foil，Shim，UNS N07725，EFORU

British Specs:，American Specs:ASTM B805，German Specs:

### **Product Introduction: Alloy 725 / Inconel 725 Foil & Shim Stock (UNS N07725)** #### **Overview** **Alloy 725 Foil & Shim Stock** (commercially known as **Inconel® 725 Foil & Shim**) represents the thin-gauge form of this advanced nickel-chromium-molybdenum-niobium alloy, precision-rolled to exacting thickness tolerances for specialized corrosive service applications. This product form combines the alloy's exceptional corrosion resistance in sour gas (H₂S-containing) environments, acidic solutions, and chloride-containing media with the versatility of thin, formable material. Inconel 725 foil is particularly valued for its ability to be formed in the annealed condition and then precipitation-hardened to achieve high strength and maintain corrosion resistance up to 650°C (1200°F) in final assemblies. The material's unique combination of properties makes it ideal for precision spacing, sealing, and electrical applications in extreme corrosive environments where conventional materials would rapidly degrade. --- #### **Chemical Composition** The chemical composition of Alloy 725 Foil & Shim (UNS N07725) maintains the same rigorous standards as other product forms: | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | 55.0 - 59.0 | | **Chromium (Cr)** | 19.0 - 22.5 | | **Molybdenum (Mo)** | 7.0 - 9.5 | | **Iron (Fe)** | 5.0 - 9.0 | | **Niobium (Nb)** | 2.75 - 4.00 | | **Titanium (Ti)** | 1.0 - 1.7 | | **Aluminum (Al)** | 0.35 - 0.75 | | **Manganese (Mn)** | ≤ 0.35 | | **Silicon (Si)** | ≤ 0.20 | | **Carbon (C)** | ≤ 0.03 | | **Sulfur (S)** | ≤ 0.010 | | **Copper (Cu)** | ≤ 0.20 | | **Phosphorus (P)** | ≤ 0.015 | *The optimized composition provides effective precipitation hardening through gamma double prime [γ'' Ni₃Nb] phase formation, even in thin foil configurations.* --- #### **Physical Properties** Special considerations for thin foil and shim applications: | Property | Metric Value | Imperial Value | | :--- | :--- | :--- | | **Density** | 8.31 g/cm³ | 0.300 lb/in³ | | **Melting Range** | 1320 - 1360 °C | 2410 - 2480 °F | | **Specific Heat (20°C)** | 442 J/kg·K | 0.106 Btu/lb·°F | | **Thermal Conductivity (20°C)** | 10.8 W/m·K | 75.0 Btu·in/hr·ft²·°F | | **Thermal Expansion Coefficient (20-100°C)** | 12.9 μm/m·°C | 7.2 μin/in·°F | | **Modulus of Elasticity** | 206 GPa | 29.9 x 10⁶ psi | | **Electrical Resistivity** | 1.28 μΩ·m | - | --- #### **Mechanical Properties & Tempers** Properties tailored for thin-gauge applications: **Annealed Condition (Formable):** * **Tensile Strength:** 900-1050 MPa (130-152 ksi) * **Yield Strength:** 550-700 MPa (80-102 ksi) * **Elongation:** 25-35% **Precipitation Hardened Condition:** * **Tensile Strength:** 1100-1240 MPa (160-180 ksi) * **Yield Strength:** 760-895 MPa (110-130 ksi) * **Elongation:** 15-25% * **Hardness:** 30-38 HRC --- #### **International Standards & Specifications** Specialized standards for foil and shim products: **Dimensional Standards:** * **ASTM B906:** General Requirements for Flat-Rolled Nickel and Nickel Alloys * **ASTM B670:** Plate, Sheet, and Strip **NACE Standards:** * **NACE MR0175/ISO 15156:** Suitable for use in H₂S-containing environments * **NACE MR0103:** Resistance to sulfide stress cracking **Quality Standards:** * **MIL-SPEC-MSRR-7130:** Shim Stock, Metallic * **Customer Specifications:** Often supplied to detailed customer drawings **Thickness Ranges:** * **Foil:** 0.025 - 0.15 mm (0.001 - 0.006 inches) * **Shim Stock:** 0.05 - 1.5 mm (0.002 - 0.060 inches) --- #### **Product Applications** **Oil & Gas Industry:** * **Sealing Elements:** Gaskets, seal strips for sour service applications * **Instrumentation:** Diaphragm seals, pressure sensor components * **Electrical Components:** Corrosion-resistant electrical contacts and springs * **Spacer Shims:** Precision shims for valve assemblies and control systems **Chemical Processing:** * **Reactor Seals:** Thin foil gaskets for corrosive chemical reactors * **Sensor Components:** Corrosion-resistant sensor diaphragms and elements * **Electrical Insulation:** High-temperature electrical insulation components * **Sealing Strips:** Continuous seals for corrosive fume handling equipment **Marine & Offshore:** * **Marine Electronics:** Corrosion-resistant contacts and springs * **Instrumentation:** Sensor components for seawater applications * **Sealing Systems:** Marine-grade gaskets and seal shims **Power Generation:** * **FGD Systems:** Sealing components for flue gas desulfurization equipment * **Sensor Applications:** Corrosion-resistant sensor elements * **Electrical Components:** High-temperature electrical contacts --- #### **Key Advantages** * **Precision Thickness Control:** Exceptional gauge consistency (±0.0025mm) * **Exceptional Corrosion Resistance:** Superior performance in sour gas and chloride-containing environments * **Superior Surface Quality:** Various finishes (2B, BA, polished, matte) * **Excellent Formability:** Can be stamped, blanked, and formed in annealed condition * **High Strength-to-Weight Ratio:** Exceptional strength in minimal cross-sections * **Outstanding Pitting Resistance:** High resistance to pitting and crevice corrosion * **Stress Corrosion Cracking Resistance:** Superior resistance to SCC in chloride environments * **Good Spring Properties:** Adequate elastic modulus and springback characteristics **Processing Capabilities:** * **Precision Slitting:** Width control to ±0.025mm * **Blanking:** Custom shapes and profiles * **Heat Treatment:** Precise thermal processing for property optimization * **Surface Treatment:** Passivation, cleaning, and special coatings * **Inspection:** 100% dimensional verification and surface quality control **Available Forms:** * **Coils:** Widths from 2mm to 600mm (0.080" to 24") * **Sheets:** Custom cut-to-size panels * **Pre-cut Shims:** Standard and custom shapes * **Surface Finishes:** 2B, bright annealed, polished, matte **Heat Treatment Specifications:** * **Solution Treatment:** 980-1010°C (1800-1850°F) followed by rapid cooling * **Aging Treatment:** 620-650°C (1150-1200°F) for 8-12 hours, air cool * **Special Processing:** Custom heat treatments for specific applications **Corrosion Performance:** * **Critical Pitting Temperature (ASTM G48):** > 85°C (185°F) * **Critical Crevice Temperature (ASTM G48):** > 65°C (150°F) * **Sulfide Stress Cracking:** Resistant per NACE MR0175 **Note:** *Inconel® is a registered trademark of Special Metals Corporation. Alloy 725 foil and shim products are typically supplied in the annealed condition for optimum formability, with subsequent aging treatment to develop the optimal combination of strength and corrosion resistance. Special handling and storage in controlled environments are recommended to prevent surface damage and contamination. Custom certifications including NACE MR0175 compliance and material traceability are available to meet specific application requirements for sour service 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 1817 gallon liquid totes Special package is available on request.