Alloy 625 / UNS N06625
MATERIAL DESCRIPTION
Alloy 625 is a nickel-chromium-molybdenum alloy with additional of niobium. This provides a high strength alloy without a strengthening heat treatment. The alloy is especially resistant to pitting and crevice corrosion but also other severely corrosive environments. Service temperatures range from cryogenic to about 1000°C. High tensile, creep, and rupture strength together with outstanding fatigue and thermal-fatigue strength in addition to oxidation resistance and excellent weldability are characteristics of this alloy.
Applications
Alloy 625 is used in oil gas industry, marine engineering, chemical processing and pollution control equipment.
Heat Treatment
Solution Annealed at 890 to 1080°C.
Weldability
Very good.
Chemical composition
| Weight % | C | Si | Mn | S | P | Cr | Ni | Mo | Nb+Ta | Co | Fe |
| Min. | 20,00 | 58,00 | 8,00 | 3,15 | |||||||
| Max. | 0,10 | 0,50 | 0,50 | 0,015 | 0,015 | 23,00 | 10,00 | 4,15 | 1,00 | 5,00 |
Product Standards: EN 10228, ASTM B446
Approvals: NACE MR0175, NORSOK M650, NORSOK M630 MDS N01
Mechanical properties
| Yield strenght Rp0.2, MPA |
Tensile strength Rm, MPa |
Elongation [%] |
Hardness [HRC] |
Impact Charpy-V, -196ºC [J] |
Pre |
| ≥ 350 | ≥ 770 | ≥ 25 | ≤ 287 | ≥ 46 |
Round bar stock
| DIA | KG/M |
| 12,7 mm | 1.1 |
| 17 mm | 2. |
| 20 mm | 2.8 |
| 25,4 mm | 4.5 |
| 32 mm | 6.8 |
| 38 mm | 9.9 |
| 45 mm | 13.8 |
| 52 mm | 18.3 |
| 57 mm | 22.1 |
| 61 mm | 24.8 |
| 66 mm | 29. |
| 71 mm | 34.5 |
| 76,2 mm | 39.5 |
| 81 mm | 44.7 |
| 87 mm | 51.5 |
| 91 mm | 56.4 |
| 102 mm | 71.3 |
| DIA | KG/M |
| 107 mm | 77.9 |
| 113 mm | 86.8 |
| 120 mm | 97.6 |
| 128 mm | 111.4 |
| 135 mm | 124. |
| 142 mm | 137.5 |
| 152 mm | 158 |
| 165 mm | 186 |
| 180 mm | 221 |
| 185 mm | 233 |
| 203 mm | 281 |
| 230 mm | 360 |
| 254 mm | 439 |
| 280 mm | 533 |
| 300 mm | 613 |
| 350 mm | 833 |
Equivalent standards
- EN 2.4856
- UNS N06625
- Alloy 625