EN 1.7725 +QT1 Steel vs. EN 1.7725 +QT2 Steel
Both EN 1.7725 +QT1 steel and EN 1.7725 +QT2 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 1.7725 +QT1 steel and the bottom bar is EN 1.7725 +QT2 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 250 | |
| 300 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 14 | |
| 14 |
| Fatigue Strength, MPa | 390 | |
| 550 |
| Impact Strength: V-Notched Charpy, J | 34 | |
| 35 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 830 | |
| 1000 |
| Tensile Strength: Yield (Proof), MPa | 610 | |
| 860 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 440 | |
| 440 |
| 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 | 39 | |
| 39 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.4 | |
| 7.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.6 | |
| 8.6 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.9 | |
| 2.9 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 1.8 |
| Embodied Energy, MJ/kg | 24 | |
| 24 |
| Embodied Water, L/kg | 54 | |
| 54 |
Common Calculations
| PREN (Pitting Resistance) | 2.8 | |
| 2.8 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 110 | |
| 130 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 980 | |
| 1940 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 29 | |
| 35 |
| Strength to Weight: Bending, points | 25 | |
| 28 |
| Thermal Diffusivity, mm2/s | 11 | |
| 11 |
| Thermal Shock Resistance, points | 24 | |
| 29 |
Alloy Composition
| Carbon (C), % | 0.27 to 0.34 | |
| 0.27 to 0.34 |
| Chromium (Cr), % | 1.3 to 1.7 | |
| 1.3 to 1.7 |
| Iron (Fe), % | 95.7 to 97.5 | |
| 95.7 to 97.5 |
| Manganese (Mn), % | 0.6 to 1.0 | |
| 0.6 to 1.0 |
| Molybdenum (Mo), % | 0.3 to 0.5 | |
| 0.3 to 0.5 |
| Phosphorus (P), % | 0 to 0.025 | |
| 0 to 0.025 |
| Silicon (Si), % | 0 to 0.6 | |
| 0 to 0.6 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Vanadium (V), % | 0.050 to 0.15 | |
| 0.050 to 0.15 |