EN 1.7221 +QT1 Steel vs. EN 1.7221 +QT2 Steel
Both EN 1.7221 +QT1 steel and EN 1.7221 +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 1.7221 +QT1 steel and the bottom bar is EN 1.7221 +QT2 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 200 | |
| 230 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 17 | |
| 11 |
| Fatigue Strength, MPa | 290 | |
| 390 |
| Impact Strength: V-Notched Charpy, J | 38 | |
| 20 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Tensile Strength: Ultimate (UTS), MPa | 650 | |
| 780 |
| Tensile Strength: Yield (Proof), MPa | 430 | |
| 630 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 420 | |
| 420 |
| 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 | 44 | |
| 44 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.3 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.4 | |
| 8.4 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.4 | |
| 2.4 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 1.5 |
| Embodied Energy, MJ/kg | 20 | |
| 20 |
| Embodied Water, L/kg | 51 | |
| 51 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 98 | |
| 83 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 490 | |
| 1050 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 23 | |
| 27 |
| Strength to Weight: Bending, points | 21 | |
| 24 |
| Thermal Diffusivity, mm2/s | 12 | |
| 12 |
| Thermal Shock Resistance, points | 19 | |
| 23 |
Alloy Composition
| Carbon (C), % | 0.22 to 0.29 | |
| 0.22 to 0.29 |
| Chromium (Cr), % | 0.8 to 1.2 | |
| 0.8 to 1.2 |
| Iron (Fe), % | 96.8 to 98.3 | |
| 96.8 to 98.3 |
| Manganese (Mn), % | 0.5 to 0.8 | |
| 0.5 to 0.8 |
| Molybdenum (Mo), % | 0.15 to 0.3 | |
| 0.15 to 0.3 |
| 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 |