SA 266 Specification for carbon steel forgings for pressure vessel components.
Chemical requirements
| ELEMENTS | COMPOSITION, ％ | ||
Grade 1 & 2 | Grade 3 | Grade 4 | |
C | 0.30 | 0.35 | 0.30 |
Mn | 0.40-1.05 | 0.80-1.35 | 0.80-1.35 |
P | 0.025 | 0.025 | 0.025 |
| S | 0.025 | 0.025 | 0.025 |
| Si | 0.15-0.35 | 0.35 | 0.15-0.35 |
Mechanical properties
Grade 1 | Grade 2 & 4 | Grade 3 | |
| Tensile strength, min. Mpa | 415-585 | 485-655 | 515-690 |
Yield strength, min. Mpa | 205 | 250 | 260 |
| Elongation in. 2 or 50 mm, min, ％ | 23 | 20 | 19 |
Reduction of area, min. ％ | 38 | 33 | 30 |
