HK40 (UNS J94204) chemical composition
Pressure-containing version of HK under ASTM A351, with a narrow carbon window for consistent creep properties. Long used for reformer tubes, headers and fittings in high-temperature pressure service.
- Designation
- HK40
- Material no.
- UNS J94204
- Standard
- ASTM A351
- Also known as
- HK-40, 25Cr-20Ni-0.4C, ≈ 1.4848
- Family
- Heat-resistant cast steel
Chemical composition (mass %)
| Element | min | max |
|---|---|---|
| CCarbon | 0.35 | 0.45 |
| SiSilicon | – | 1.75 |
| MnManganese | – | 1.50 |
| PPhosphorus | – | 0.04 |
| SSulphur | – | 0.04 |
| CrChromium | 23.0 | 27.0 |
| NiNickel | 19.0 | 22.0 |
| MoMolybdenum | – | 0.50 |
| FeIron | remainder | |
Basis of values: Limits per ASTM A351.
We cast HK40
We produce heat-resistant castings by sand casting, and by centrifugal casting for cylindrical parts such as rings, bushings and sleeves. Every heat is analysed by OES; heat treatment, CNC machining in the group's Perama machine shop and EN 10204 3.1 certificates are available.
- 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.