Properties
Properties
Mechanical properties
Metallic coated high-strength steel grades have the following mechanical properties (skin-passed) - these are measured transverse to the rolling direction:
Phosphorus-alloyed steels
| Grade | CR P220 | |
|---|---|---|
| Coating type | GI/GA | |
| Yield strength ReL | N/mm2 | 220 - 280 |
| Tensile strength Rm | N/mm2 | 340 - 400 |
| Elongation | % | 32 |
| Min. r-value | 1.3 | |
| Min. n-value | 0.15 |
Not in EN 10346:2015. Tata Steel’s own specification.
Lower yield strength or 0.2% proof stress applies.
For galvannealed grades (ZF) the minimum elongation before fracture is lowered by 2%.
Elongation after fracture A uses test piece length L0 = 80 mm.
For galvannealed grades (ZF) the minimum r90-value is lowered by 0.2.
Phosphorus-alloyed steels are currently not available with MagiZinc® coatings.
Chemical composition
Tata Steel supplies the following cast analysis with maximum values unless otherwise shown:
Phosphorus-alloyed steels
| Grade | CR P220-GI/GA/ZM | |
|---|---|---|
| C | Max. | 0.08 |
| Mn | Max. | 0.7 |
| P | Max. | 0.1 |
| S | Max. | 0.025 |
| Si | Max. | 0.5 |
| Altot | Min. | 0.015 |
| Ti | Max. | - |
| Nb | Max. | - |