Inconel® 625 (UNS N06625)
Chromium-Molybdenum-Niobium Alloy
What Is Inconel® 625?
Inconel® 625 (UNS N06625) is a solid-solution strengthened, austenitic nickel-chromium-molybdenum-niobium alloy engineered for exceptional strength and corrosion resistance in extreme environments. It maintains high mechanical strength from cryogenic temperatures up to 1800°F (982°C), making it ideal for demanding applications such as turbine exhaust systems, heat exchanger tubing, seawater piping, and chemical processing equipment.
Strength is derived from molybdenum and niobium within the nickel-chromium matrix — eliminating the need for precipitation hardening while ensuring consistent, stable performance across a wide temperature range.
Inconel 625 offers outstanding resistance to oxidation, carburization, pitting, crevice corrosion, and chloride stress corrosion cracking. It performs exceptionally well in seawater, thermal systems, and high-temperature processing equipment, making it one of the most versatile high-performance nickel alloys available.
Inconel® 625 Standards and Designations
Common Names & Cross-References
Trade Names | Inconel® 625, Alloy 625, Inco 625, Nicrofer® 6020 hMo, Chronin® 625, Haynes® 625 |
UNS | N06625 |
German (W.Nr. / DIN) | 2.4856 — NiCr22Mo9Nb |
British Standard | BS 3072 / 3074 / 3076 NA21 |
French (AFNOR) | NC22DNb |
EN (Europe) | NiCr22Mo9Nb |
Japanese (JIS) | NCF625 |
Properties of Inconel 625®
Inconel 625® Chemical Composition
| Nickel (Ni) | 58.0 min |
| Chromium (Cr) | 20.0 – 23.0 |
| Molybdenum (Mo) | 8.0 – 10.0 |
| Niobium (Nb + Ta) | 3.15 – 4.15 |
| Iron (Fe) | 5.0 max |
| Cobalt (Co) | 1.0 max |
| Manganese (Mn) | 0.50 max |
| Silicon (Si) | 0.50 max |
| Aluminum (Al) | 0.40 max |
| Titanium (Ti) | 0.40 max |
| Carbon (C) | 0.10 max |
| Phosphorus (P) | 0.015 max |
| Sulfur (S) | 0.015 max |
Typical Mechanical Properties (Annealed)
| Property | Typical | Spec Min |
|---|---|---|
| Tensile Strength | 135 ksi (930 MPa) | 120 ksi |
| Yield Strength (0.2%) | 75 ksi (517 MPa) | 60 ksi |
| Elongation (in 2 in.) | 45% | 30% |
| Hardness | Rockwell B 92 | B 100 max |
About Inconel 625®
Key Features & Advantages
- Excellent corrosion resistance across a wide range of aggressive environments
- Outstanding performance in chloride-rich and seawater applications
- High strength from cryogenic temperatures up to 1800°F (982°C)
- Resistance to pitting, crevice corrosion, and intergranular attack
- Exceptional resistance to chloride stress corrosion cracking (SCC)
- Strong oxidation and carburization resistance at elevated temperatures
- Excellent fabrication characteristics
- No precipitation hardening required — stable, consistent properties
Common Applications of Inconel 625®
- Gas turbine exhaust ducting and transition liners
- Heat exchanger tubing, tube sheets, and thermal systems
- Reaction vessels, distillation columns, and bubble caps
- Aerospace engine exhaust systems and ducting
- Seawater piping, offshore, and subsea components
- Furnace hardware and high-temperature processing equipment
- Bellows, expansion joints, and flexible components
Primary Markets Served
- Power Generation & Gas Turbines
- Chemical Processing
- Aerospace & Defense
- Marine & Offshore
- Pollution Control
When to Specify Inconel 625®
- Inconel 625 vs. 718 — 625 is solid-solution strengthened with superior corrosion resistance and consistent properties without aging. 718 is precipitation-hardened for much higher strength but lower corrosion performance and a 1300°F service ceiling.
- Inconel 625 vs. Hastelloy C-276 — Both are NiCrMo alloys. C-276 typically outperforms 625 in localized chloride pitting and crevice corrosion. 625 has higher strength and better high-temperature performance.
- Inconel 625 vs. 316L stainless — 625 is the upgrade for chloride-bearing seawater, chemical processing, or any environment where 316L pits or cracks. Cost is higher but service life and reliability are dramatically better.
- Inconel 625 vs. Inconel 600 — 625 has significantly better corrosion resistance due to the molybdenum and niobium additions. 600 is preferred for high-temperature oxidation in nuclear and furnace service.
Why Source 21?
- ISO 9001-certified quality system with full chemistry and mechanical traceability on every shipment
- Multi-million dollar national inventory across stainless, nickel alloys, copper, and brass
- Strong domestic and international mill relationships, including premium specialty mill partnerships
- In-house slitting, edging, leveling, and cut-to-length capabilities
- Contract programs, blanket orders, and vendor-managed inventory (VMI) for production accounts
- Responsive technical support for tight-tolerance and certification-driven work
Request A Quote
Contact Source 21 today for Hastelloy Inconel 625 pricing, availability, and processing options. Our team responds quickly, asks the right questions, and gets you accurate quotes on real material — not vague placeholders.
Call 631-821-1101 or request a quote online to get started.