Austenitic stainless steels are the most frequently investment-cast corrosion-resistant alloys. Cast grades are balanced to contain a small amount of delta ferrite, which improves resistance to hot tearing and to weld cracking; their composition limits therefore differ from the wrought grades whose names they are often given informally.
Grades in this family
| Grade | Type | UNS | Standard | Tensile strength Rm, min. (MPa) | Yield strength Rp0.2, min. (MPa) |
|---|---|---|---|---|---|
| CF8 | Austenitic stainless steel, cast 304 type | J92600 | ASTM A351/A351M, A743/A743M | 485 | 205 |
| CF3 | Low-carbon austenitic stainless steel, cast 304L type | J92500 | ASTM A351/A351M, A743/A743M | 485 | 205 |
| CF8M | Mo-bearing austenitic stainless steel, cast 316 type | J92900 | ASTM A351/A351M, A743/A743M | 485 | 205 |
| CF3M | Low-carbon Mo-bearing austenitic stainless steel, cast 316L type | J92800 | ASTM A351/A351M, A743/A743M | 485 | 205 |
| CN7M | High-nickel austenitic alloy with Mo and Cu, cast Alloy 20 type | N08007 | ASTM A351/A351M, A743/A743M, A744/A744M | 425 | 170 |
| CK3MCuN | 6 % Mo superaustenitic stainless steel | J93254 | ASTM A351/A351M, A743/A743M, A744/A744M | 550 | 260 |
Minimum values (or ranges) for separately cast test bars as specified in
Casting and processing considerations
Castings are normally solution annealed and rapidly cooled to dissolve carbides and restore corrosion resistance. Low-carbon grades are preferred where castings will be welded without subsequent heat treatment. High shrinkage requires adequate feeding of heavy sections; surface finish and pickling or passivation requirements should be agreed in advance.
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.