Nickel-based casting alloys cover two different needs: resistance to severe corrosion in acids, chlorides and seawater (Ni-Cr-Mo and Ni-Cu alloys), and strength with oxidation resistance at high temperature (precipitation-strengthened superalloys). Investment casting is the standard forming route for many of these alloys because they are difficult and costly to machine.
Grades in this family
| Grade | Type | UNS | Standard | Tensile strength Rm, min. (MPa) | Yield strength Rp0.2, min. (MPa) |
|---|---|---|---|---|---|
| CW-12MW | Ni-Mo-Cr-W alloy, cast Alloy C type | N30002 | ASTM A494/A494M | 495 | 275 |
| CW-2M | Low-carbon Ni-Mo-Cr alloy, cast Alloy C-4 type | N26455 | ASTM A494/A494M | 495 | 275 |
| CW-6MC | Ni-Cr-Mo-Nb alloy, cast Alloy 625 type | N26625 | ASTM A494/A494M | 485 | 275 |
| M-35-1 | Nickel-copper alloy, cast Alloy 400 type | N24135 | ASTM A494/A494M | 450 | 170 |
| CY-40 | Ni-Cr-Fe alloy, cast Alloy 600 type | N06040 | ASTM A494/A494M | 485 | 195 |
| Alloy 718 | Precipitation-hardening Ni-Cr-Fe-Nb superalloy | N07718 | SAE AMS 5383 (investment castings) | — | — |
Minimum values (or ranges) for separately cast test bars as specified in
Casting and processing considerations
Melting practice has a strong influence on quality: reactive elements such as aluminium and titanium in superalloys normally require vacuum melting and pouring, while corrosion-resistant grades are commonly air melted with careful control of carbon and silicon. Corrosion-resistant grades are solution annealed; weld repair and its heat treatment must follow the material specification.
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.