Alloy 725，Inconel 725 Pipe，UNS N07725，EFORU

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

### **Product Introduction: Alloy 725 / Inconel 725 Pipe (UNS N07725)** #### **Overview** **Alloy 725 Pipe** (commercially known as **Inconel® 725 Pipe**) is a high-performance nickel-chromium-molybdenum-niobium alloy piping product specifically engineered for severe corrosive service conditions requiring exceptional corrosion resistance combined with high strength. This precipitation-hardenable alloy maintains outstanding performance in aggressive environments including sour gas (H₂S-containing) wells, acidic solutions, and chloride-containing media, while providing excellent mechanical properties at temperatures up to 650°C (1200°F). The pipe is manufactured through advanced thermo-mechanical processes and controlled heat treatments to ensure uniform microstructure, consistent wall thickness, and reliable performance in critical oil and gas, chemical processing, and marine applications. The alloy's enhanced characteristics are achieved through a sophisticated precipitation-hardening mechanism involving gamma prime [γ'] and gamma double prime [γ''] phase formation, providing an optimal balance of strength and corrosion resistance for demanding piping applications. --- #### **Chemical Composition** The chemical composition of Alloy 725 Pipe (UNS N07725) is carefully balanced for optimal performance: | 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 piping system design and 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% * **Hardness:** 30-40 HRC **Pressure Performance:** * **Maximum Working Pressure:** Varies with pipe size and wall thickness * **Temperature Rating:** Up to 650°C (1200°F) continuous service * **Burst Pressure:** Excellent resistance to internal pressure deformation --- #### **International Standards** Alloy 725 Pipe conforms to several international specifications: **ASTM Standards:** * **ASTM B829:** Standard Specification for Seamless Nickel and Nickel Alloy Pipe and Tube * **ASTM B705:** Standard Specification for Nickel-Alloy Welded Pipe * **ASTB B804:** UNS N07718 Welded Pipe **ASME Standards:** * **ASME SB829:** Specification for Seamless Nickel and Nickel Alloy Pipe and Tube * **ASME SB705:** Nickel-Alloy Welded Pipe **NACE Standards:** * **NACE MR0175/ISO 15156:** Suitable for use in H₂S-containing environments * **NACE MR0103:** Resistance to sulfide stress cracking **Other International Standards:** * **ISO 6207:** Nickel and nickel alloy pipes * **DIN 17750:** Nickel and nickel alloy pipes - Technical delivery conditions * **GB/T 2882:** Chinese standard for nickel and nickel alloy pipes --- #### **Product Applications** Alloy 725 pipes serve critical functions across multiple high-performance industries: **Oil & Gas Industry:** * **Downhole Tubing:** Production tubing, casing strings for sour gas wells * **Surface Piping:** Flow lines, gathering lines, and process piping * **Subsea Systems:** Risers, jumpers, and manifold piping * **Well Intervention:** Coiled tubing and workstring applications **Chemical Processing:** * **Process Piping:** Corrosive chemical transport systems * **Heat Exchanger Tubes:** High-temperature heat exchanger applications * **Reactor Systems:** Process reactor feed and discharge lines * **Acid Services:** Piping for hydrochloric, sulfuric, and phosphoric acid handling **Marine & Offshore:** * **Seawater Systems:** Cooling water pipes, seawater intake lines * **Offshore Platforms:** Process piping, utility lines, injection systems * **Desalination Plants:** Brine handling pipes, product water lines **Power Generation:** * **FGD Systems:** Flue gas desulfurization system piping * **Chemical Injection:** Ammonia, amine, and other chemical injection lines * **Wastewater Treatment:** Corrosive effluent handling pipes --- #### **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 * **Pressure Integrity:** Excellent resistance to internal and external pressure deformation * **Good Fabricability:** Can be bent, formed, and fabricated using standard pipe working equipment * **Excellent Weldability:** Can be welded using conventional methods with proper technique * **Long Service Life:** Maintains performance in aggressive environments over extended periods **Available Forms & Sizes:** * **Seamless Pipe:** OD from 6mm to 400mm (0.25" to 16") * **Welded Pipe:** OD from 6mm to 1200mm (0.25" to 48") * **Wall Thickness:** Schedule 5S to XXS, custom thickness available * **Lengths:** Random lengths, double random, or cut-to-size **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 **Note:** *Inconel® is a registered trademark of Special Metals Corporation. Alloy 725 pipes are available in seamless and welded configurations, with various schedules and sizes to meet specific application requirements. Proper installation, including appropriate support and expansion considerations, is essential for optimal performance in corrosive service. Comprehensive certification including chemical analysis, mechanical properties, and corrosion testing reports are provided for 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 1809 gallon liquid totes Special package is available on request.