S550Q is a quenched and tempered high-strength steel plate, which is a special alloy steel. The impact performance is specified at a temperature of no less than -20 degrees; the impact performance at a temperature of no less than -40 degrees is specified as: L; The impact performance at a temperature of -70 degrees is recorded as: L1.
Chemical composition % of steel S550Q (1.8904):
| C | Si | Mn | Ni | P | S | Cr | Mo | V | N | Nb | Ti | Cu | Zr | B | CEV |
| max 0.2 | max 0.8 | max 1.7 | max 2 | max 0.025 | max 0.015 | max 1.5 | max 0.7 | max 0.12 | max 0.015 | max 0.06 | max 0.05 | max 0.5 | max 0.15 | max 0.005 | max 0.83 |
Mechanical properties of steel S550Q (1.8904):
| Nominal thickness (mm): | 3 - 100 | 100 - 150 |
| Rm - Tensile strength (MPa) | 640-820 | 590-770 |
| Nominal thickness (mm): | 3 - 50 | 50 - 100 | 100 - 150 |
| ReH - Minimum yield strength (MPa) | 550 | 530 | 490 |
| KV - Impact energy (J) longitud., | 0° 40 |
-20° 30 |
| A - Min. elongation Lo = 5,65 √ So (%) | 16 |
