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
Annealing at minimum 871°C and water quench.
Weldability
Very good.
Chemical Composition
Weight % | C | Mn | P | S | Si | Cr | Ni | Mo | Nb+Ta | Co | Fe | Al | Ti |
Min. | 20,0 | 58,0 | 8,0 | 3,15 | |||||||||
Max. | 0,10 | 0,50 | 0,015 | 0,015 | 0,50 | 23,0 | 10,0 | 4,15 | 1,00 | 5,00 | 0,40 | 0,40 |
Reference Standards
General:
- PED 2014/68/EU Annex I section 4.3
- NACE MR0175/ISO 15156-3 and NACE MR0103/ISO 17945
Bars:
-
ASTM B446, ASTM B564, Norsok M-630 MDS N17
Mechanical Properties (Specific for Bars)
Dimension (mm) |
Yield strength Rp0.2, MPa |
Tensile strength Rm, MPa |
Elongation [%] |
Hardness [HB] |
Impact Charpy-V, -60ºC [J] |
≤ 102 | ≤ 414 | ≥ 827 | ≥ 30 | ≤ 321 | ≥ 68 |
≤ 254 | ≤ 345 | ≥ 758 | ≥ 30 | ≤ 321 | ≥ 68 |
> 254 | ≥ 345 | ≥ 758 | ≥ 30 | ≤ 321 | ≥ 42 |
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