EN 1.4122 +QT750 Steel vs. EN 1.4034 +QT800 Steel
Both EN 1.4122 +QT750 steel and EN 1.4034 +QT800 steel are iron alloys. Both are furnished in the quenched and tempered condition. They have a very high 95% of their average alloy composition in common.
For each property being compared, the top bar is EN 1.4122 +QT750 steel and the bottom bar is EN 1.4034 +QT800 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 190 |
| Elongation at Break, % | 14 | |
| 11 |
| Fatigue Strength, MPa | 360 | |
| 400 |
| Impact Strength: V-Notched Charpy, J | 11 | |
| 14 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Shear Modulus, GPa | 77 | |
| 76 |
| Shear Strength, MPa | 520 | |
| 540 |
| Tensile Strength: Ultimate (UTS), MPa | 850 | |
| 900 |
| Tensile Strength: Yield (Proof), MPa | 630 | |
| 730 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 270 |
| Maximum Temperature: Corrosion, °C | 400 | |
| 390 |
| Maximum Temperature: Mechanical, °C | 870 | |
| 770 |
| Melting Completion (Liquidus), °C | 1440 | |
| 1440 |
| Melting Onset (Solidus), °C | 1400 | |
| 1390 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 15 | |
| 30 |
| Thermal Expansion, µm/m-K | 10 | |
| 11 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.2 | |
| 3.1 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.5 | |
| 3.7 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 9.5 | |
| 7.0 |
| Density, g/cm3 | 7.7 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 2.4 | |
| 2.0 |
| Embodied Energy, MJ/kg | 33 | |
| 27 |
| Embodied Water, L/kg | 120 | |
| 100 |
Common Calculations
| PREN (Pitting Resistance) | 20 | |
| 14 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 110 | |
| 94 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1000 | |
| 1370 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 31 | |
| 32 |
| Strength to Weight: Bending, points | 26 | |
| 27 |
| Thermal Diffusivity, mm2/s | 4.0 | |
| 8.1 |
| Thermal Shock Resistance, points | 30 | |
| 32 |
Alloy Composition
| Carbon (C), % | 0.33 to 0.45 | |
| 0.43 to 0.5 |
| Chromium (Cr), % | 15.5 to 17.5 | |
| 12.5 to 14.5 |
| Iron (Fe), % | 77.2 to 83.4 | |
| 83 to 87.1 |
| Manganese (Mn), % | 0 to 1.5 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0.8 to 1.3 | |
| 0 |
| Nickel (Ni), % | 0 to 1.0 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.015 |