Seamless pipe
ASTM A335 P21 — chemistry & properties
ASTM A335 P21 (Seamless pipe, UNS K31545): chemical composition and mechanical properties. 3Cr-1Mo high-temperature piping
Chemical composition (wt %)
| C | 0.05 – 0.15 |
| Mn | 0.3 – 0.6 |
| P | ≤ 0.025 |
| S | ≤ 0.025 |
| Si | ≤ 0.5 |
| Cr | 2.65 – 3.35 |
| Mo | 0.8 – 1.06 |
Mechanical properties
| Tensile strength, min | 415 MPa |
| Yield strength, min | 205 MPa |
| Elongation, min | 30 % |
| Hardness | Not specified |