UNS N07725 (Inconel 725)
Generic Name & Other Designation
Inconel 725®, Alloy 725, Nickel Alloy 725, W.Nr. 2.4807, NiCr21Mo9NbTi (DIN/EN)
Product Overview
UNS N07725 (often designated Inconel 725) is an age-hardenable nickel-chromium-molybdenum-niobium alloy that combines the broad corrosion resistance of Alloy 625 with the extreme mechanical strength of an age-hardened superalloy.
Because its high strength is developed through thermal precipitation rather than cold working, large-section forgings maintain uniform mechanical properties throughout the cross-section. This makes UNS N07725 an essential specification for heavy-section oilfield components.
Key Highlights
✅ Precipitation-Hardened Ultra High Strength: Yield strength twice that of Alloy 625, achieved through age-hardening (gamma double prime phase formation with Nb, Ti, Al) without sacrificing ductility.
✅ Extreme Sour Gas (H2S) Immunity: Designed specifically for downhole oil & gas environments containing high levels of hydrogen sulfide, chlorides, and elemental sulfur.
✅ Pitting & Crevice Attack Defenses: High molybdenum (7-9.5%) and chromium balance yields an elevated PREN, protecting critical components against localized pitting.
✅ Resistance to Hydrogen Embrittlement: Resistant to stress corrosion cracking (SCC) and hydrogen-assisted cracking under high pressure and temperature (HPHT).
✅ Precision Machined Supplies by BELNADE: Premium forged bars, valve shafts, and threaded stock certified for offshore oilfield deployment.
Chemical Composition & Physical Properties
1. Chemical Composition (Weight %)
Element | Ni | Cr | Mo | Nb | Ti | Al | Fe | C | Mn | Si |
Min (%) | 55.0 | 19.0 | 7.0 | 2.75 | 1.0 | 0.35 | Bal. | — | — | — |
Max (%) | 59.0 | 22.5 | 9.5 | 4.00 | 1.7 | 0.50 | (~9.0) | 0.03 | 0.35 | 0.20 |
2. Mechanical Properties (Age-Hardened Condition)
Parameter | Value / Standard (Age-Hardened Condition) |
Density | 8.31 g/cm³ (0.300 lb/in³) |
Melting Range | 1271°C – 1343°C (2320°F – 2450°F) |
Tensile Strength (Rm) | ≥ 1205 MPa (175 ksi) |
Yield Strength (0.2%, Rp0.2) | ≥ 827 MPa (120 ksi) |
Elongation (A5) | ≥ 20% |
Hardness | 36 – 44 HRC |
Available Forms & Specifications
BELNADE delivers high-grade UNS N07725 mill products for demanding projects:
Forged Bars & Heavy Rounds: API 6A / NACE compliant forged stock up to 300mm diameter.
Custom Valve Shafts & Stems: Rough-machined or finish-machined to client drawings.
Fasteners & Threaded Rods: High-strength stud bolts, cap screws, and locking nuts.
Forged Blocks & Rings: Custom open-die forgings for subsea equipment.
Typical Application Scenarios
Downhole Oil & Gas (Sour Service): Hanger nipples, polished bore receptacles (PBRs), packers, and subsea safety valves.
Subsea Production Systems: High-strength riser bolts, umbilical connectors, and hydraulic control shafts.
Marine Defense: Fasteners and high-load drive shafts operating in deep-sea marine environments.
Chemical Processing: High-pressure pump shafts and acid-resistant valve internals.
Quality Assurance & Verification
All UNS N07725 products supplied by BELNADE undergo rigorous verification:
NACE MR0175 / ISO 15156 Certification
Solution Heat Treatment & Age Hardening Traceability
Ultrasonic Inspection per ASTM A388 / SEP 1921
Charpy V-Notch Impact & Tensile Testing
Supplier Profile: BELNADE
BELNADE is a global supplier specializing in high-strength oilfield alloys and corrosion-resistant materials, serving pump manufacturers, valve makers, and energy EPC contractors.
Get in Touch with BELNADE for Quotes and Technical Inquiries
📧 Email: [email protected]
🌐 Website: www.belnade-material.com
💬 Mobile/ WhatsApp: +86 183 6997 5713