Designation
- Grade
- CA40
- UNS
- J91153
- EN designation
- —
- Commonly associated designations
- 420 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 A743/A743M
- Density
- ≈ 7.61 g/cm³
- Usual delivery condition
- Quenched (or normalised) and tempered
Chemical composition
| Element | Mass fraction, % |
|---|---|
| C | 0.20–0.40 |
| Mn | ≤ 1.00 |
| Si | ≤ 1.50 |
| Cr | 11.5–14.0 |
| Ni | ≤ 1.0 |
| Mo | ≤ 0.5 |
| 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. (%) |
|---|---|---|---|
| Quenched (or normalised) and tempered | 690 | 485 | 15 |
Minimum values (or ranges) for separately cast test bars as specified in ASTM A743/A743M.
Characteristics
- Corrosion and oxidation behaviour
- Moderate resistance: atmosphere, fresh water and mild media
- Weldability
- Limited; crack-sensitive, welding only by agreement
- Machinability
- Good in the appropriate heat-treatment condition
- Typical applications
- Valves Pumps Turbine components General engineering
International cross-reference
| System | Designation | Relationship |
|---|---|---|
| AISI | 420 (wrought) | Comparable properties |
Casting and processing considerations
Properties depend entirely on correct heat treatment, so the required condition must be stated on the drawing or order. Martensitic grades are crack-sensitive during cooling and welding; preheating and controlled tempering are standard practice. For precipitation-hardening grades, homogenisation before solution treatment is often specified for heavier sections.
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.