Designation
- Grade
- CK20
- UNS
- J94202
- EN designation
- —
- Commonly associated designations
- 310 type
Type designations and trade names are given for orientation only. Trade names are trademarks of their respective owners; the cast grade and its standard remain the specification. - Standard
- ASTM A351/A351M, A743/A743M
- Family
- Heat-resistant steels
- Density
- ≈ 7.75 g/cm³
- Usual delivery condition
- Solution annealed and quenched
Chemical composition
| Element | Mass fraction, % |
|---|---|
| C | ≤ 0.20 |
| Mn | ≤ 2.00 |
| Si | ≤ 2.00 |
| Cr | 23.0–27.0 |
| Ni | 19.0–22.0 |
| Fe | bal. |
Main elements only. Phosphorus, sulphur and residual-element limits are specified in the standard and are not reproduced here.
Mechanical properties
| Condition | Tensile strength Rm, min. (MPa) | Yield strength Rp0.2, min. (MPa) | Elongation, min. (%) |
|---|---|---|---|
| Solution annealed and quenched | 450 | 195 | 30 |
Minimum values (or ranges) for separately cast test bars as specified in ASTM A351/A351M, A743/A743M.
Characteristics
- Corrosion and oxidation behaviour
- Designed for oxidation resistance and strength at high temperature
- Weldability
- Possible with qualified procedure; preheat and/or post-weld heat treatment as specified
- Machinability
- Moderate; work hardening or built-up edge to be considered
- Typical applications
- Furnace parts High-temperature service Chemical processing Energy
International cross-reference
| System | Designation | Relationship |
|---|---|---|
| AISI | 310 (wrought) | Comparable properties |
Casting and processing considerations
Usually supplied as cast, without heat treatment. Room-temperature ductility is limited and decreases after service exposure, so designs should avoid sharp notches and allow for thermal expansion. Acceptance is commonly based on chemical composition; high-temperature properties are design data rather than routine release tests.
Reference data compiled from the cited standards for orientation. Always work from the current edition of the governing specification; values are not a guaranteed LOSTWAX TR delivery specification.