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. Property range is indicated according to EN 10346, but properties meet equivalent VDA 239-100 specifications also.
Bake-hardening steels
| Grade | CR BH220 | |
|---|---|---|
| Coating type | GI/GA/ZM | |
| Yield strength ReL | N/mm2 | 220 - 280 |
| Min. BH2 | N/mm2 | 35 |
| Tensile strength Rm | N/mm2 | 320 - 400 |
| Elongation | % | 32 |
| Min. r-value r90 | 1.2 | |
| Min. n-value n90 | 0.15 |
Lower yield strength or 0.2% proof stress applies.
BH2 refers to the increase of 0.2% proof stress after heating (bake hardening). Not applicable for hot rolled substrate.
Elongation after fracture A uses test piece length L0 = 80 mm.
For galvannealed grades (GA) the minimum elongation before fracture is lowered by 2%.
For galvannealed grades (ZF) the minimum r90-value is lowered by 0.2.
Chemical composition
Tata Steel supplies the following cast analysis with maximum values unless otherwise shown:
Bake-hardening steels
| Grade | CR BH220-GI/GA/ZM | |
|---|---|---|
| C | Max. | 0.1 |
| Mn | Max. | 0.7 |
| P | Max. | 0.08 |
| S | Max. | 0.025 |
| Si | Max. | 0.5 |
| Altot | Max. | 0.1 |
| Ti | Max. | 0.12 |
| Nb | Max. | 0.09 |