ASTM A204 is a standard for pressure vessel with molybdenum alloy plates. The standard ASTM A204 includes three grades ASTM A204GrA, ASTM A204GrB, ASTM A204GrC. For ASTM A204 GrA steel plate, the max thickness is 150mm and for A204 GrB steel plate, the max thickness is 150mm, while for A204 GrC steel plate, the max thickness is 100mm.
A204GrA, A204GrB, A204GrC steel plate chemical composition:
| Standard | Grade | Thickkness | Chemical composition % | |||||
| mm | C | Mn | Si | P | S | Mo | ||
| ASTM A204 | A204 GrA | ≤25 | ≤0.18 | ≤0.98 | 0.13-0.45 | ≤0.035 | ≤0.035 | 0.41-0.64 |
| >25-50 | ≤0.21 | |||||||
| >50-100 | ≤0.23 | |||||||
| >100 | ≤0.25 | |||||||
| A204 GrB | ≤25 | ≤0.20 | ≤0.98 | 0.13-0.45 | ≤0.035 | ≤0.035 | 0.41-0.64 | |
| >25-50 | ≤0.23 | |||||||
| >50-100 | ≤0.25 | |||||||
| >100 | ≤0.27 | |||||||
| A204 GrC | ≤25 | ≤0.23 | ≤0.98 | 0.13-0.45 | ≤0.035 | ≤0.035 | 0.41-0.64 | |
| >25-50 | ≤0.26 | |||||||
| >50-100 | ≤0.28 | |||||||
| >100 | ≤0.28 | |||||||
A204GrA, A204GrB, A204GrC steel plate mechanical properties:
| Standard | Grade | Yield strength min |
Tensile strength | Elongation % min |
|
| Mpa | Mpa | T=200mm | T=50mm | ||
| ASTM A204 | A204 GrA | 255 | 450-585 | 19 | 23 |
| A204 GrB | 275 | 485-620 | 17 | 21 | |
| A204 GrC | 295 | 515-655 | 16 | 20 | |
A204GrA, A204GrB, A204GrC steel plate supplementary requirements:
Other main additional technical requirements from customers :
S1. Vacuum Treatment
S2. Product Analysis
S3. Simulated Post-Weld Heat Treatment
S4. Additional Tension Test
S5.Charpy V-Notch Impact Test
S6.Drop Weight Test
S7.High-Temperature Tension Test
S8. Ultrasonic Examination in accordance with - A 435/A 435M
S9.Magnetic Particle Examination
S11.Ultrasonic Examination in accordance with A 577/A 577M
S12.Ultrasonic Examination in accordance with A 578/A 578M
S17.vacuum carbon deoxidized steel
