Nickel-based alloys
2.4858
Alloy 825
NiCr21Mo
Titanium-stabilised nickel-iron-chromium-molybdenum alloy for chemical and offshore service, resistant to sulphuric and phosphoric acid and to chloride stress-corrosion cracking.
Chemical composition
mass %| Element | Content |
|---|---|
| CCarbon | ≤0.025 |
| SiSilicon | ≤0.5 |
| MnManganese | ≤1 |
| PPhosphorus | ≤0.03 |
| SSulphur | ≤0.15 |
| CrChromium | 19.5–23.5 |
| MoMolybdenum | 2.5–3.5 |
| NiNickel | 38–46 |
| TiTitanium | 0.6–1.2 |
| AlAluminium | ≤1.2 |
| CoCobalt | ≤1 |
| CuCopper | 1.5–3 |
| FeIron | balance |
Mechanical properties
room temperature- Rp0.2 min (N/mm²)
- 240
- Rp1.0 min (N/mm²)
- 265
- Rm (N/mm²)
- 585–793
- Elongation A% (longitudinal)
- 30
- Impact energy KV J (longitudinal)
- 150
- Impact energy KV J (transverse)
- 100
Cold-finished, 5–100 mm.
Standard equivalences
- DIN/EN
- NiCr21Mo
- AISI
- Alloy 825
- UNS
- N08825
- AFNOR
- NC 21 FeDU
- BS
- NA 16
- Source datasheet prints P as 0.25% (implausible) and Ti as '0.6–0.12'; corrected here to P ≤ 0.03% and Ti 0.6–1.2% per the standard. Verify before specifying.
Typical applications
- Offshore and heat exchangers
- Chemical industry
- Phosphoric- and sulphuric-acid plant
- Caustic-soda evaporators, nuclear engineering
Frequently asked questions
What is 2.4858 (Alloy 825)?
2.4858 (NiCr21Mo) — Nickel-based alloys. Titanium-stabilised nickel-iron-chromium-molybdenum alloy for chemical and offshore service, resistant to sulphuric and phosphoric acid and to chloride stress-corrosion cracking.
Which grades are equivalent to 2.4858?
2.4858 corresponds to EN NiCr21Mo; equivalent designations: AISI Alloy 825, UNS N08825, AFNOR NC 21 FeDU, BS NA 16.
Related grades
Indicative values — verify against the applicable standard before specifying.
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