China · GB
85
GB/T 1222:2016 — Spring steels
Chemical composition
| Element | min | max | Similar | Remarks |
|---|---|---|---|---|
| C | 0.82 | 0.9 | ||
| Cr | 0.25 | |||
| Cu | 0.25 | |||
| Mn | 0.5 | 0.8 | ||
| Ni | 0.35 | |||
| P | 0.03 | |||
| S | 0.03 | |||
| Si | 0.17 | 0.37 |
Mechanical properties
| Heat treatment / condition | Yield strength | Tensile strength | Elongation | Reduction of area | Impact energy | Hardness |
|---|---|---|---|---|---|---|
| quenched and tempered | ≥980 | ≥1130 | ≥6 | ≥30 | ||
| hot rolled | HB ≤302 |
Heat treatment
| Type | 3 | 4 |
|---|---|---|
| Heat-treatment process | 淬火+回火 | 淬火温度820℃，淬火介质油，回火温度480℃。 |