China · GB
85
GB 3279:1989 — Hot-rolled spring steel sheets
Chemical composition
| Element | min | max | Similar | Remarks |
|---|---|---|---|---|
| C | 0.82 | 0.9 | ||
| Cr | 0.25 | |||
| Cu | 0.25 | |||
| Mn | 0.5 | 0.8 | ||
| Ni | 0.25 | |||
| P | 0.035 | |||
| S | 0.035 | |||
| Si | 0.17 | 0.37 |
Mechanical properties
| Heat treatment / condition | Yield strength | Tensile strength | Elongation | Reduction of area | Impact energy | Hardness |
|---|---|---|---|---|---|---|
| hot rolled steel plates, annealed | ≥800 | ≥10 | ||||
| sheet, annealed, 3 < t <= 15 mm | ≥785 | ≥10 | ||||
| sheet, annealed, t <= 3 mm | ≥800 | ≥10 |