COMPREHENSIVE TECHNICAL ANALYSIS AND DATASHEET OF INCONEL 625 (UNS N06625)
Inconel 625 is a nickel-chromium-molybdenum superalloy widely recognized for its high strength, excellent fabricability, and outstanding corrosion resistance across a broad temperature spectrum, from cryogenic levels up to 982°C (1800°F). Unlike many other superalloys, the strength of Inconel 625 is derived from the solid-solution strengthening effect of molybdenum (Mo) and niobium (Nb) on the nickel-chromium matrix.
Because of this solid-solution strengthening, precipitation-hardening treatments are not required to achieve its high mechanical performance. Inconel 625 acts as the industry standard for environments where standard stainless steels and even some nickel alloys fail due to extreme temperature or aggressive chemical exposure.
■ Product Overview
| Material Classification | Nickel-Chromium-Molybdenum Superalloy |
|---|---|
| UNS Designation | N06625 |
| Common Trade Names | Alloy 625, Nickel 625, Haynes 625®, Inconel 625® |
| Magnetic State | Non-magnetic (Annealed); Permeability ≈ 1.0006 |
| Corrosion Resistance | Exceptional resistance to pitting, crevice corrosion, and SCC |
| Fabricability | Excellent weldability and formability |
| Primary Strengthening | Solid Solution (Niobium and Molybdenum) |
| Standard Heat Treatment | Mill Annealed (typically 1052°C ± 14°C) |
■ Proprietary Datasheet Download
Professionals can access our high-fidelity Inconel 625 technical library, featuring deformation mechanism maps, creep properties, and iso-corrosion curves.
Inconel 625 / UNS N06625 — Complete Technical Datasheet
Contains empirical data for stress simulations, torque-tension values, and predictive performance modeling in sulfuric, hydrochloric, and phosphoric acids.
⬇ DOWNLOAD DATASHEET■ Chemical Composition
The performance of Inconel 625 is rooted in its precise elemental balance. The high nickel and chromium content provide resistance to oxidizing environments, while molybdenum and niobium prevent localized chloride-induced attack.
| Element | Weight % (UNS N06625) |
|---|---|
| Nickel (Ni) | 58.0 min |
| Chromium (Cr) | 20.0 – 23.0 |
| Molybdenum (Mo) | 8.0 – 10.0 |
| Niobium + Tantalum (Nb + Ta) | 3.15 – 4.15 |
| Iron (Fe) | 5.0 max |
| Manganese (Mn) | 0.50 max |
| Silicon (Si) | 0.50 max |
| Carbon (C) | 0.10 max |
| Cobalt (Co) | 1.0 max |
| Aluminum (Al) | 0.40 max |
| Titanium (Ti) | 0.40 max |
| Sulfur (S) | 0.015 max |
| Phosphorus (P) | 0.015 max |
■ Mechanical Properties
Inconel 625 maintains its structural integrity across a massive thermal range. It is particularly noted for its high fatigue strength and resistance to stress-corrosion cracking.
| Mechanical Property | Typical Value (Annealed) |
|---|---|
| Ultimate Tensile Strength (UTS) | ≈ 827 – 930 MPa (120 – 135 ksi) |
| 0.2% Yield Strength | ≈ 414 – 517 MPa (60 – 75 ksi) |
| Elongation (% in 50mm) | 30% – 50% |
| Hardness (Rockwell B) | 94 – 100 HRB |
| Hardness (Brinell) | 175 – 240 HB |
| Elastic Modulus (RT) | 205 – 207 GPa (30 × 10⁶ psi) |
| Density | 8.44 g/cm³ (0.305 lb/in³) |
■ Equivalent Grades
Due to its widespread use in global aerospace and offshore sectors, Inconel 625 is cataloged under several international numbering systems.
| Standard / System | Designation |
|---|---|
| UNS (USA) | N06625 |
| W.Nr (Germany) | 2.4856 |
| AFNOR (France) | NC22DNB4M |
| JIS (Japan) | NCF 625 |
| BS (UK) | NA 21 |
| GOST (Russia) | ХН75МБТЮ |
| ISO | NiCr22Mo9Nb |
■ Applications & Industries
Inconel 625's versatility makes it a critical material for high-stress, corrosive environments.
- Marine Engineering: Used for mooring cables, propeller blades, submarine exhaust ducts, and transducer controls due to its freedom from pitting and high corrosion-fatigue strength.
- Aerospace: Applied in aircraft ducting systems, engine exhaust systems, thrust-reverser systems, and rocket thrust-chamber tubing.
- Chemical Processing: Ideal for reaction vessels, distillation columns, bubble caps, and transfer piping handling aggressive acids and chlorides.
- Nuclear Industry: Selected for reactor core and control-rod components in advanced reactor concepts due to its high allowable design strength at elevated temperatures.
- Power & Pollution Control: Used in flue gas desulfurization (FGD) systems and scrubbers where resistance to acidic condensate is required.
■ Fastener Types Available
Ananka Group provides precision-engineered Inconel 625 fasteners designed to survive high-pressure and high-temperature environments.
- Bolts: Hex Head Bolts, Socket Head Cap Screws, Heavy Hex Bolts, U-Bolts, Eye Bolts, and Custom Forged Bolts.
- Nuts: Hex Nuts, Heavy Hex Nuts, Nylock Nuts, Jam Nuts, and Lock Nuts.
- Screws: Machine Screws, Set Screws, and Custom Precision Screws.
- Washers: Flat Washers, Spring Washers, Locking Washers, and Square Washers.
- Studs: Fully Threaded Rods, Double-End Studs, and Tap-End Studs.
■ Standards & Specifications
Inconel 625 fasteners and components are manufactured to rigorous ASTM and ASME specifications to ensure material integrity and safety.
- ASTM B446 / ASME SB446: Standard specification for Inconel 625 Rod and Bar.
- ASTM B443 / ASME SB443: Specification for Plate, Sheet, and Strip.
- ASTM B444 / ASME SB444: Specification for Seamless Pipe and Tube (Grade 1 Annealed and Grade 2 Solution Annealed).
- ASTM B564 / ASME SB564: Specification for Forgings.
- AMS 5599 / AMS 5666: Aerospace Material Specifications for sheet and bar respectively.
■ MTC
Traceability is paramount in critical sectors like nuclear and aerospace. Ananka Group provides comprehensive Material Test Certificates (MTC) to validate compliance.
- EN 10204 Type 3.1: This certificate, issued by our independent quality department, provides the specific heat-traceable test results for chemical composition and mechanical properties of the batch.
- EN 10204 Type 3.2: For the most critical "lethal service" or offshore applications, we facilitate third-party validation (e.g., TUV, BV, or SGS) to witness testing and co-sign the certification.
■ Why Choose Ananka Group for Inconel 625?
Ananka Group stands as a premier manufacturing-driven organization in Mumbai, specializing in high-performance exotic alloys.
- Manufacturing Expertise: We utilize hot forging for large-diameter fasteners (up to M100) and precision CNC machining for custom components.
- Advanced Threading: Our cold roll threading process ensures superior grain flow and high fatigue strength, which is critical for high-tensile superalloy fasteners.
- Certifications: PED 2014/68/EU certified by TÜV Rheinland, ensuring our fasteners are approved for pressure equipment in global export projects.
- Global Supply Chain: With a base in Mumbai and an established presence in the USA and UK, we offer competitive pricing and reliable international logistics.
■ Frequently Asked Questions
1. Is Inconel 625 magnetic?
Inconel 625 is naturally non-magnetic and paramagnetic. In the annealed state, it has a magnetic permeability of approximately 1.0006. It is suitable for applications where magnetic interference must be avoided, such as sensitive electronic instruments.
2. What is the difference between Grade 1 and Grade 2 Inconel 625?
Grade 1 is furnished in the annealed condition and is typically used for service temperatures up to 593°C (1100°F). Grade 2 is solution annealed and is specified for service above 593°C where resistance to creep and rupture is critical.
3. How does Inconel 625 compare to Inconel 718?
Inconel 625 is a solid-solution strengthened alloy that provides superior weldability and better aqueous corrosion resistance. Inconel 718 is a precipitation-hardened alloy that offers higher strength at room temperature but is restricted to a lower maximum service temperature (approx. 700°C vs 1000°C for 625).
4. Can Inconel 625 be hardened by heat treatment?
No, Inconel 625 cannot be hardened by heat treatment. Its high strength is a result of the alloying elements Mo and Nb. Increased hardness can only be achieved through cold working, which may introduce a very slight magnetic response.
5. What is the maximum service temperature for Inconel 625?
While it has oxidation resistance up to 982°C (1800°F), for long-term load-bearing service, it is best restricted to 593°C (1100°F) to avoid embrittlement from deleterious phase precipitation (delta phase).
6. Why is Niobium (Nb) added to Inconel 625?
Niobium, acting in conjunction with molybdenum, serves to stiffen the alloy's matrix, providing high mechanical strength without the need for a separate strengthening heat treatment.
■ Secure Your Critical Infrastructure
For technical consultation on Inconel 625 fastening solutions or to request a quote for your project, contact the Ananka Group Sales Team at sales@anankafasteners.com or via WhatsApp at +91 86557 47687. Our engineers are ready to assist with material selection and custom fabrication to meet your most demanding specifications.