United States · SAE
4640
SAE AMS 6317J:2012 — Steel Bars and Forgings 1.8Ni.0.25Mo (0.38.0.43C) (4640) Heat Treated,125 ksi (862 MPa) Tensile Strength UNS K22440
Chemical composition
| Element | min | max | Similar | Remarks |
|---|---|---|---|---|
| C | 0.38 | 0.43 | ||
| Cr | 0.2 | |||
| Cu | 0.35 | |||
| Mn | 0.6 | 0.8 | ||
| Mo | 0.2 | 0.3 | ||
| Ni | 1.65 | 2 | ||
| P | 0.025 | |||
| S | 0.025 | |||
| Si | 0.15 | 0.35 |
Mechanical properties
| Heat treatment / condition | Yield strength | Tensile strength | Elongation | Reduction of area | Impact energy | Hardness |
|---|---|---|---|---|---|---|
| bars, forgings, quenched and tempered | ≤689 | ≤862 | ≤16 | ≤50 | ||
| bars, HB | 锻件 淬火及回火 ≤262 |