Quenched And Tempered SAE-AISI 4340 vs. EN 1.4122 +QT750 Steel
Both quenched and tempered SAE-AISI 4340 and EN 1.4122 +QT750 steel are iron alloys. Both are furnished in the quenched and tempered condition. They have 83% of their average alloy composition in common. There are 30 material properties with values for both materials. Properties with values for just one material (4, in this case) are not shown.
For each property being compared, the top bar is quenched and tempered SAE-AISI 4340 and the bottom bar is EN 1.4122 +QT750 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 200 |
| Elongation at Break, % | 14 | |
| 14 |
| Fatigue Strength, MPa | 740 | |
| 360 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 73 | |
| 77 |
| Shear Strength, MPa | 730 | |
| 520 |
| Tensile Strength: Ultimate (UTS), MPa | 1210 | |
| 850 |
| Tensile Strength: Yield (Proof), MPa | 1150 | |
| 630 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 280 |
| Maximum Temperature: Mechanical, °C | 430 | |
| 870 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1440 |
| Melting Onset (Solidus), °C | 1420 | |
| 1400 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 480 |
| Thermal Conductivity, W/m-K | 44 | |
| 15 |
| Thermal Expansion, µm/m-K | 13 | |
| 10 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.5 | |
| 2.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.6 | |
| 2.5 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 3.5 | |
| 9.5 |
| Density, g/cm3 | 7.8 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 1.7 | |
| 2.4 |
| Embodied Energy, MJ/kg | 22 | |
| 33 |
| Embodied Water, L/kg | 53 | |
| 120 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 170 | |
| 110 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 3490 | |
| 1000 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 43 | |
| 31 |
| Strength to Weight: Bending, points | 32 | |
| 26 |
| Thermal Diffusivity, mm2/s | 12 | |
| 4.0 |
| Thermal Shock Resistance, points | 36 | |
| 30 |
Alloy Composition
| Carbon (C), % | 0.38 to 0.43 | |
| 0.33 to 0.45 |
| Chromium (Cr), % | 0.7 to 0.9 | |
| 15.5 to 17.5 |
| Iron (Fe), % | 95.1 to 96.3 | |
| 77.2 to 83.4 |
| Manganese (Mn), % | 0.6 to 0.8 | |
| 0 to 1.5 |
| Molybdenum (Mo), % | 0.2 to 0.3 | |
| 0.8 to 1.3 |
| Nickel (Ni), % | 1.7 to 2.0 | |
| 0 to 1.0 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 to 0.040 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.015 |