Designation
- Grade
- CB7Cu-1
- UNS
- J92180
- Standard
- ASTM A747/A747M
- Density
- ≈ 7.80 g/cm³
- Usual delivery condition
- Solution treated and precipitation hardened
Chemical composition
| Element | Mass fraction, % |
|---|---|
| C | ≤ 0.07 |
| Mn | ≤ 0.70 |
| Si | ≤ 1.00 |
| Cr | 15.50–17.70 |
| Ni | 3.60–4.60 |
| Cu | 2.50–3.20 |
| Nb | 0.15–0.35 |
| N | ≤ 0.05 |
| 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. (%) |
|---|---|---|---|
| H900 | 1170 | 1000 | 5 |
| H1025 | 1035 | 965 | 9 |
| H1150 | 860 | 670 | 10 |
Minimum values (or ranges) for separately cast test bars as specified in ASTM A747/A747M.
Characteristics
- Corrosion and oxidation behaviour
- Good general corrosion resistance
- 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
- Aerospace Pumps Impellers Structural parts General engineering
International cross-reference
| System | Designation | Relationship |
|---|---|---|
| EN | 1.4525 (GX5CrNiCu16-4), EN 10283 | Similar composition |
| JIS | SCS24 (G 5121) | Similar composition |
| UNS (wrought) | S17400 (17-4 PH) | 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 delivery specification.