Designation
- Grade
- CD3MN (4A)
- UNS
- J92205
- Standard
- ASTM A890/A890M, A995/A995M Gr. 4A
- Density
- ≈ 7.80 g/cm³
- Usual delivery condition
- Solution annealed and quenched
Chemical composition
| Element | Mass fraction, % |
|---|---|
| C | ≤ 0.03 |
| Mn | ≤ 1.50 |
| Si | ≤ 1.00 |
| Cr | 21.0–23.5 |
| Ni | 4.5–6.5 |
| Mo | 2.5–3.5 |
| Cu | ≤ 1.00 |
| N | 0.10–0.30 |
| 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 | 620 | 415 | 25 |
Minimum values (or ranges) for separately cast test bars as specified in ASTM A890/A890M, A995/A995M Gr. 4A.
Characteristics
- Corrosion and oxidation behaviour
- High resistance to chloride pitting, crevice and stress corrosion cracking
- Weldability
- Possible with qualified procedure; preheat and/or post-weld heat treatment as specified
- Machinability
- Difficult; rigid set-ups, low cutting speeds or grinding
- Typical applications
- Valves Pumps Offshore Marine Chemical processing
International cross-reference
| System | Designation | Relationship |
|---|---|---|
| EN | 1.4470 (GX2CrNiMoN22-5-3), EN 10283 | Similar composition |
| UNS (wrought) | S31803 / S32205 | Comparable properties |
Casting and processing considerations
The phase balance and freedom from intermetallic phases such as sigma depend on a correct solution anneal followed by rapid quenching; slow cooling of heavy sections is the main risk. Ferrite content, impact toughness and corrosion testing are frequently specified as acceptance tests and should be defined at the enquiry stage.
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.