Alloy 725，Inconel 725 Fittings，UNS N07725，EFORU

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

### **Product Introduction: Alloy 725 / Inconel 725 Fittings (UNS N07725)** #### **Overview** **Alloy 725 Fittings** (commercially known as **Inconel® 725 Fittings**) are precision-engineered components designed for critical piping and tubing systems operating in severe corrosive environments. These fittings leverage the exceptional properties of Alloy 725, including superior corrosion resistance in sour gas (H₂S-containing) wells, acidic environments, and chloride-containing solutions, combined with high strength up to 650°C (1200°F). Manufactured through advanced forging, machining, and forming processes, Inconel 725 fittings maintain structural integrity and leak-proof performance in the most demanding oil and gas, chemical processing, and marine applications. The unique precipitation-hardening characteristics of Alloy 725, achieved through gamma prime [γ'] and gamma double prime [γ''] phase formation, ensure that these fittings maintain their mechanical properties and corrosion resistance even after prolonged exposure to aggressive service conditions. --- #### **Chemical Composition** The chemical composition of Alloy 725 Fittings (UNS N07725) conforms to strict international standards: | 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 excellent corrosion resistance while enabling effective precipitation hardening through gamma double prime [γ'' Ni₃Nb] phase formation.* --- #### **Physical Properties** Critical properties for fitting design and system engineering: | 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** Enhanced mechanical properties achieved through optimized heat treatment: **Solution Annealed + Aged Condition:** * **Ultimate Tensile Strength:** 1100-1240 MPa (160-180 ksi) * **Yield Strength (0.2% Offset):** 760-895 MPa (110-130 ksi) * **Elongation:** 15-25% * **Reduction of Area:** 35-50% * **Hardness:** 30-40 HRC **Pressure Performance:** * **Maximum Working Pressure:** Varies with fitting design and size * **Temperature Rating:** Up to 650°C (1200°F) continuous service * **Burst Pressure:** Excellent resistance to pressure deformation --- #### **International Standards** Alloy 725 Fittings conform to numerous international specifications: **Dimensional Standards:** * **ASME B16.11:** Forged Fittings, Socket-Welding and Threaded * **MSS SP-79:** Socket-Welding Reducer Inserts * **MSS SP-97:** Integrally Reinforced Forged Branch Outlet Fittings **Material Standards:** * **ASTM B564:** Standard Specification for Nickel Alloy Forgings * **ASTM B805:** Precipitation Hardening Nickel Alloy Bars, Forgings, and Forging Stock **NACE Standards:** * **NACE MR0175/ISO 15156:** Suitable for use in H₂S-containing environments * **NACE MR0103:** Resistance to sulfide stress cracking **Quality Standards:** * **ISO 9001:** Quality Management Systems * **ASME BPVC:** Boiler and Pressure Vessel Code * **API 6A:** Wellhead and Christmas Tree Equipment --- #### **Product Applications** Alloy 725 fittings serve critical functions across multiple high-performance industries: **Oil & Gas Industry:** * **Wellhead Equipment:** Christmas tree fittings, valve connectors, wellhead adapters * **Downhole Tools:** Instrumentation fittings, control line connectors for sour service * **Subsea Systems:** Hydraulic fittings, chemical injection connectors, manifold fittings * **Surface Equipment:** Flow line fittings, gathering line connectors, process piping fittings **Chemical Processing:** * **Process Piping:** Corrosive fluid handling fittings, reactor connections * **Heat Exchangers:** Tube fittings, header connections, bundle fittings * **Pump Systems:** Suction and discharge fittings, seal piping connections * **Valve Systems:** Valve bypass fittings, instrument connections **Marine & Offshore:** * **Seawater Systems:** Cooling water pipe fittings, seawater intake connections * **Offshore Platforms:** Process piping fittings, utility line connections * **Desalination Plants:** Brine handling fittings, product water line connections **Power Generation:** * **FGD Systems:** Flue gas desulfurization system piping fittings * **Chemical Injection:** Ammonia, amine injection line fittings * **Wastewater Treatment:** Corrosive effluent handling pipe fittings --- #### **Key Advantages** * **Exceptional Corrosion Resistance:** Superior performance in sour gas and chloride-containing environments * **High Strength:** Excellent mechanical properties maintained in corrosive conditions * **Outstanding Stress Corrosion Cracking Resistance:** Superior resistance to SCC in chloride environments * **Excellent Pitting Resistance:** High resistance to pitting and crevice corrosion * **Excellent Weldability:** Can be welded to similar and dissimilar materials using conventional methods * **Superior Fatigue Performance:** Excellent resistance to vibration and pressure cycling * **Dimensional Stability:** Maintains precise tolerances under thermal cycling conditions * **Long Service Life:** Maintains performance in aggressive environments over extended periods **Available Fitting Types:** * **Socket Weld Fittings:** Elbows, tees, couplings, unions, caps * **Threaded Fittings:** NPT, BSPT, BSPP thread configurations * **Butt Weld Fittings:** Elbows, tees, reducers, caps, stub ends * **Special Fittings:** Crosses, laterals, outlet fittings, custom designs **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 * **Stress Relieving:** Available for welded components **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 **Quality Assurance:** * **Material Certification:** Complete traceability and compliance documentation * **Dimensional Inspection:** 100% verification to specified standards * **Surface Examination:** Visual and liquid penetrant testing * **Pressure Testing:** Hydrostatic and pneumatic testing capabilities **Note:** *Inconel® is a registered trademark of Special Metals Corporation. Alloy 725 fittings are typically supplied in the solution treated and aged condition to meet specific application requirements. Proper installation techniques and torque specifications must be followed to ensure optimal performance and system integrity. Comprehensive certification packages including chemical analysis, mechanical properties, and corrosion testing reports are provided for all critical 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 1814 gallon liquid totes Special package is available on request.