50Cr-50Ni-Nb (UNS R20501) chemical composition
Niobium-stabilised 50Cr-50Ni casting alloy with very low iron. Developed for fuel-ash corrosion from vanadium- and sodium-bearing residual oils; typical for tube supports, hangers and fittings in refinery heaters and oil-fired boilers.
- Designation
- 50Cr-50Ni-Nb
- Material no.
- UNS R20501
- Standard
- ASTM A560
- Also known as
- IN-657, 50/50 Cr-Ni-Nb
- Family
- Nickel & chromium-nickel casting alloys
Chemical composition (mass %)
| Element | min | max |
|---|---|---|
| CCarbon | – | 0.10 |
| SiSilicon | – | 0.50 |
| MnManganese | – | 0.30 |
| PPhosphorus | – | 0.02 |
| SSulphur | – | 0.02 |
| CrChromium | 47.0 | 52.0 |
| NNitrogen | – | 0.16 |
| NbNiobium | 1.40 | 1.70 |
| TiTitanium | – | 0.50 |
| FeIron | – | 1.00 |
| AlAluminium | – | 0.25 |
| NiNickel | remainder | |
Basis of values: Limits per ASTM A560.
Additional requirements: C + N ≤ 0.20 · Ni + Cr + Nb > 97.5
We cast 50Cr-50Ni-Nb
We cast these nickel-base and chromium-nickel alloys to the ordered standard, with spectrometer analysis of every melt, heat treatment, CNC machining in our own machine shop and EN 10204 3.1 certificates.
- Sand casting at our foundry in Mandra, Attica; centrifugal casting for bushings, sleeves and liners
- Heat treatment at the foundry (water, oil or air quench); CNC machining in our machine shop in Perama
- Spectrometer analysis of every heat, mechanical testing and NDT
- EN 10204 3.1 inspection certificates; ISO 9001 (both plants) and ISO 14001 (foundry) certified
Other grades in this family
For information only, without warranty: limits per the cited standard or, where stated, typical or house values; ≈ marks a comparable grade, not an equivalent. The current edition of the standard, the purchase order and the drawing govern.