NiCr22Mo9Nb · N06625 · Inconel 625 · ASTM B366
The most widely specified nickel alloy for structural and corrosion-resistant applications combined. 9% Mo + Nb. PRE ~51. Exceptional fatigue strength, weld-deposit hardfacing capability, and service from cryogenic to 980°C. Subsea, offshore, aerospace, marine.
Inconel 625 (UNS N06625, EN 2.4856) is unique among nickel alloys in combining high strength with broad corrosion resistance without relying on precipitation hardening. The 22% Cr provides an effective oxide film in oxidising environments, the 9% Mo delivers pitting and crevice corrosion resistance comparable to 904L stainless at elevated chloride concentrations, and the Nb stabilisation (similar to the stabilisation principle in 321/1.4541) prevents sensitisation during welding.
The result is an alloy that is simultaneously a corrosion-resistant material for seawater and acidic environments, a high-strength structural material for subsea clamp connectors and risers, a weld overlay material for carbon steel components, and a cryogenic material down to −196°C without ductile-brittle transition.
| Element | Min | Max | Role |
|---|---|---|---|
| Nickel (Ni) | 58.0% | — | Matrix, toughness |
| Chromium (Cr) | 20.0% | 23.0% | Oxidation and passivation |
| Molybdenum (Mo) | 8.0% | 10.0% | Pitting and crevice resistance |
| Niobium + Tantalum | 3.15% | 4.15% | Strengthening, sensitisation prevention |
| Iron (Fe) | — | 5.0% | — |
| Carbon (C) | — | 0.10% | — |
| Property | 625 (2.4856) | C-276 (2.4819) | 825 (2.4858) |
|---|---|---|---|
| PRE | ~51 | ~70 | ~32 |
| Yield strength | ≥414 MPa | ~345 MPa | ~240 MPa |
| Primary strength | Strength + corrosion combined | Maximum corrosion | NACE + reducing acid |
| Cryogenic use | Yes (−196°C) | Possible | Limited |
| Weld overlay | Yes — common | Possible | Not typical |
| Filler | ERNiCrMo-3 | ERNiCrMo-4 | ERNiCrMo-3 |
| EN number | 2.4856 |
| EN designation | NiCr22Mo9Nb |
| UNS | N06625 |
| Trade name | Inconel 625 |
| PRE (typical) | ~51 |
| Yield strength | ≥414 MPa |
| Max service temp | 980°C (oxidising) |
| Cryogenic | Down to −196°C |
| Filler (GTAW) | ERNiCrMo-3 |
| PWHT | Not required |
| Standard | ASTM B366; dimensions to ASME B16.9 (EN 10253 does not cover nickel alloys) |
| Certificate | EN 10204 3.1 standard |
PMI (XRF) on every order. EN 10204 3.1 standard. Charpy −196°C and NACE hardness available. Tell us your size schedule and service environment.
Get QuoteDN15–DN600 and larger. Outside diameters follow the EN 10220 / EN ISO 1127 pipe series; wall thickness is matched to your connecting pipe.
| Size | OD (mm) |
|---|---|
| DN 15 | 21.3 |
| DN 20 | 26.9 |
| DN 25 | 33.7 |
| DN 32 | 42.4 |
| DN 40 | 48.3 |
| DN 50 | 60.3 |
| DN 65 | 76.1 |
| DN 80 | 88.9 |
| DN 100 | 114.3 |
| DN 125 | 139.7 |
| DN 150 | 168.3 |
| DN 200 | 219.1 |
| DN 250 | 273.0 |
| DN 300 | 323.9 |
| DN 350 | 355.6 |
| DN 400 | 406.4 |
| DN 450 | 457.0 |
| DN 500 | 508.0 |
| DN 600 | 610.0 |
Its 9% molybdenum plus niobium gives a PRE of about 51.
From cryogenic service down to −196°C up to about 980°C in oxidising conditions.
ERNiCrMo-3 filler for GTAW; PWHT is not required. Minimum yield strength is 414 MPa.
