Alloy 825 / UNS N08825
MATERIAL DESCRIPTION
Alloy 825 is a nickel alloy with high iron content and a copper addition, suitable for applications in special corrosive environments.
Applications
Alloy 825 belongs to the group corrosion-resistant alloys, CRA. The grade provides a cost-effective offering – achieved by lowering expensive alloy content, compared to superalloys, such as Alloy 625, and Alloy 718. Alloy 825 is a very versatile alloy with resistance to corrosion in acids and alkalis under both oxidizing and reducing conditions. Due to the high nickel content, the alloy has superior immunity to stress corrosion cracking. The corrosion resistance in various media like phosphoric, nitric, sulfuric, and organic acids is good. It also shows good corrosion resistance in seawater, caustic chloride alkalis, and ammoniac.
The properties of Alloy 825 are more stable and less temperature-dependent compared to many other corrosion-resistant alloys such as the super duplex stainless steel grades. Alloy 825 can therefore safely be used for applications at both cryogenic and elevated temperatures.
Heat Treatment
Annealing at 930–980 °C (1706–1796°F) followed by quenching in water.
Weldability
Good.
Chemical Composition
| (nominal) % | C | Mn | P | S | Si | Cr | Ni | Mo | Nb+Ta | Cu | Fe | Al | Ti |
| <0,03 | 0,7 | <0,03 | <0,03 | 0,4 | 22,5 | 40,5 | 3,4 | 2,0 | 0,15 | 0,8 |
Reference Standards
General:
- PED 2014/68/EU
- NACE MR0175 / MR0103
Bars:
- ASTM B425, ASME SB-425
- Random lengths 3-6,9 meters
- Tolerances as per ISO K12,plain ends
Mechanical Properties (Specific for Bars)
| Yield strength Rp0.2, MPa |
Tensile strength Rm, MPa |
Elongation [%] |
Hardness [HB] |
| ≥ 241 | ≥ 586 | ≥ 30 | ≤ 327 |
| DIA | KG/M |
| 100 | 64,00 |
| 110 | 77,37 |
| 130 | 107,91 |
| 140 | 125,08 |
| 160 | 163,22 |
Equivalent Standards
- EN 2.4858
- UNS N08825
- Alloy 825