Forged flanges & fittings
ASTM A182 F91 — chemistry & properties
ASTM A182 F91 (Forged flanges & fittings, UNS K90901): chemical composition and mechanical properties. 9Cr-1Mo-V power-plant steam service
Chemical composition (wt %)
| C | 0.08 – 0.12 |
| Mn | 0.3 – 0.6 |
| P | ≤ 0.02 |
| S | ≤ 0.01 |
| Si | 0.2 – 0.5 |
| Cr | 8 – 9.5 |
| Ni | ≤ 0.4 |
| Mo | 0.85 – 1.05 |
| N | 0.03 – 0.07 |
Mechanical properties
| Tensile strength, min | 620 MPa |
| Yield strength, min | 415 MPa |
| Elongation, min | 20 % |
| Hardness | 190–248 HBW |