4340 Alloy Steel can be heat treated to achieve high strength whilst maintaining good toughness, wear resistance and fatigue strength levels, combined with strength up to 315 ºC.
| % | Fe | Ni | Cr | Mn | C | Mo | Si | S | P |
|---|---|---|---|---|---|---|---|---|---|
| Min | 95.195 | 1.65 | 0.70 | 0.60 | 0.37 | 0.20 | 0.15 | - | - |
| Max | 96.33 | 2 | 0.90 | 0.80 | 0.43 | 0.30 | 0.30 | 0.04 | 0.035 |
4340 Alloy Steel is an iron-based alloy containing nickel, chromium and molybdenum. The relatively high carbon content provides this alloy with superior strength in applications where severe service conditions exist.
4340 Alloy Steel has high strength, superior toughness and good ductility. In addition, the alloy is immune to embrittlement.
To learn more about 4340 Alloy Steel contact us today, or fill in our online quote form and we’ll get right back to you!
| Mechanical & Physical Properties | 21.1°C | 100°C | 204.4°C | 315.6°C | 400°C | 537.8°C | 648.9°C | 700°C | 760°C | 815°C | 870°C | 982°C |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ultimate Tensile Strength /MPa | 792 | - | - | - | - | 726 | 473 | - | 286 | - | 139 | 66 |
| 407 | - | - | - | - | 363 | 275 | - | 152 | - | 68 | 31 | |
| - | - | - | - | - | - | - | - | - | - | - | - | |
| 31 | - | - | - | - | 27 | 32 | - | 75 | - | 90 | 91 | |
| - | - | - | - | - | - | 83 | 47 | 26 | 15 | 8.3 | - | |
| - | 11 | 12.7 | 13.4 | 13.9 | 14.3 | 15 | 15.4 | - | 16.5 | 17.1 | 18.2 | |
| 10.06 | - | - | - | - | - | - | - | - | - | - | - | |
| 221 | 216 | 210 | 203 | 197 | 190 | 181 | 173 | - | 165 | 153 | 140 |
| Room Temperature Mechanical & Physical Properties at Various Tempering Temperature (Normalised at 899-927 °C/Austenitised at 816-829°C/Oil Quenched) | 204°C | 260°C | 316°C | 427°C | 538°C | 593°C | 649°C |
|---|---|---|---|---|---|---|---|
| Ultimate Tensile Strength /MPa | 1905 | 1830 | 1140 | ||||
| 0.2% Yield Strength /MPa | 1530 | 1530 | 1035 | ||||
| Reduction of area % | 35 | 25 | 60 | ||||
| Elongation % | 11 | 8 | 18 | ||||
| Room Temperature Hardness/ Rockwell C at Various Tempering Temperature (Austenitised at 843°C/Oil Quenched/Tempered Twice for 2+2 Hours) | 52 | 47 | 41 | 35 | 25 |
| Hardness/ Rockwell C at Various Testing Temperature | 21 °C | 93°C | 204°C | 316°C | 427°C | 538°C |
|---|---|---|---|---|---|---|
| Condition A: Normalised at 899 °C for 1 hour + air cool/ Austenitised at 816 °C for 0.5 hour + oil quench/ Tempered at 246 °C for 2+2 hours +air cool | 49 | 48.5 | 48 | 45.5 | 35 | 18 |
| Condition B: Normalised at 899 °C for 1 hour + air cool/ Austenitised at 816 °C for 0.5 hour + oil quench/ Tempered at 482 °C for 2+2 hours +air cool | 40.5 | 38 | 36.5 | 34 | 31.5 | 18 |
| Condition C: Normalised at 899 °C for 1 hour + air cool/ Austenitised at 802 °C for 0.5 hour + oil quench/ Tempered at 593 °C for 2 hours +air cool | 34 | 32.5 | 30 | 27.5 | 24 | 13 |
Proud members of the British Valve & Actuator Association