Forged flanges & fittings
ASTM A182 F21 — chemistry & properties
ASTM A182 F21 (Forged flanges & fittings, UNS K31545): chemical composition and mechanical properties. 3Cr-1Mo forgings for hydrogen and high-temperature service
Chemical composition (wt %)
| C | 0.05 – 0.15 |
| Mn | 0.3 – 0.6 |
| P | ≤ 0.04 |
| S | ≤ 0.04 |
| Si | ≤ 0.5 |
| Cr | 2.7 – 3.3 |
| Mo | 0.8 – 1.06 |
Mechanical properties
| Tensile strength, min | 515 MPa |
| Yield strength, min | 310 MPa |
| Elongation, min | 20 % |
| Hardness | 156–207 HBW |