Designation
- Grade
- WC9
- UNS
- J21890
- Standard
- ASTM A217/A217M
- Density
- ≈ 7.85 g/cm³
- Usual delivery condition
- Normalised and tempered
Chemical composition
| Element | Mass fraction, % |
|---|---|
| C | 0.05–0.18 |
| Mn | 0.40–0.70 |
| Si | ≤ 0.60 |
| Cr | 2.00–2.75 |
| Mo | 0.90–1.20 |
| 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. (%) |
|---|---|---|---|
| Normalised and tempered | 485–655 | 275 | 20 |
Minimum values (or ranges) for separately cast test bars as specified in ASTM A217/A217M.
Characteristics
- Corrosion and oxidation behaviour
- Not corrosion resistant; coating or other protection required in corrosive environments
- Weldability
- Possible with qualified procedure; preheat and/or post-weld heat treatment as specified
- Machinability
- Good in the appropriate heat-treatment condition
- Typical applications
- Valves Energy High-temperature service Pressure parts
International cross-reference
| System | Designation | Relationship |
|---|---|---|
| EN | 1.7379 (G17CrMo9-10), EN 10213 | Comparable properties |
| JIS | SCPH32 (G 5151) | Comparable properties |
Casting and processing considerations
Good castability and moderate pouring temperatures. Surface decarburisation from the reaction between metal, shell and atmosphere has to be considered on heat-treated and wear surfaces; machining allowance or a controlled furnace atmosphere are common countermeasures. Section-size sensitivity of quenched and tempered grades should be reflected in the drawing requirements.
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 delivery specification.