EN 1.4415 +QT750 Steel vs. EN 1.4415 +QT850 Steel
Both EN 1.4415 +QT750 steel and EN 1.4415 +QT850 steel are variants of the same material. They share alloy composition and many physical properties, but develop different mechanical properties as a result of different processing.
For each property being compared, the top bar is EN 1.4415 +QT750 steel and the bottom bar is EN 1.4415 +QT850 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 20 | |
| 17 |
| Fatigue Strength, MPa | 470 | |
| 510 |
| Impact Strength: V-Notched Charpy, J | 110 | |
| 91 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Shear Modulus, GPa | 77 | |
| 77 |
| Shear Strength, MPa | 520 | |
| 570 |
| Tensile Strength: Ultimate (UTS), MPa | 830 | |
| 930 |
| Tensile Strength: Yield (Proof), MPa | 730 | |
| 840 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 280 |
| Maximum Temperature: Corrosion, °C | 390 | |
| 390 |
| Maximum Temperature: Mechanical, °C | 790 | |
| 790 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1460 |
| Melting Onset (Solidus), °C | 1420 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 19 | |
| 19 |
| Thermal Expansion, µm/m-K | 9.9 | |
| 9.9 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.4 | |
| 2.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.8 | |
| 2.8 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 13 | |
| 13 |
| Density, g/cm3 | 7.9 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 3.6 | |
| 3.6 |
| Embodied Energy, MJ/kg | 51 | |
| 51 |
| Embodied Water, L/kg | 120 | |
| 120 |
Common Calculations
| PREN (Pitting Resistance) | 19 | |
| 19 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 160 | |
| 150 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1350 | |
| 1790 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 29 | |
| 33 |
| Strength to Weight: Bending, points | 25 | |
| 27 |
| Thermal Diffusivity, mm2/s | 5.1 | |
| 5.1 |
| Thermal Shock Resistance, points | 30 | |
| 34 |
Alloy Composition
| Carbon (C), % | 0 to 0.030 | |
| 0 to 0.030 |
| Chromium (Cr), % | 11.5 to 13.5 | |
| 11.5 to 13.5 |
| Iron (Fe), % | 75.9 to 82.4 | |
| 75.9 to 82.4 |
| Manganese (Mn), % | 0 to 0.5 | |
| 0 to 0.5 |
| Molybdenum (Mo), % | 1.5 to 2.5 | |
| 1.5 to 2.5 |
| Nickel (Ni), % | 4.5 to 6.5 | |
| 4.5 to 6.5 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 0.5 | |
| 0 to 0.5 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.015 |
| Titanium (Ti), % | 0 to 0.010 | |
| 0 to 0.010 |
| Vanadium (V), % | 0.1 to 0.5 | |
| 0.1 to 0.5 |