Quenched and Tempered (+QT) 1.7240 Steel
EN 1.7240 +QT steel is EN 1.7240 steel in the quenched and tempered condition. The graph bars on the material properties cards below compare EN 1.7240 +QT steel to: EN wrought alloy steels (top), all iron alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Brinell Hardness
480
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
6.8 %
Fatigue Strength
870 MPa 130 x 103 psi
Impact Strength: U-Notched Charpy
9.1 J 6.7 ft-lb
Poisson's Ratio
0.29
Reduction in Area
34 %
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
940 MPa 140 x 103 psi
Tensile Strength: Ultimate (UTS)
1600 MPa 230 x 103 psi
Tensile Strength: Yield (Proof)
1480 MPa 210 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
420 °C 790 °F
Melting Completion (Liquidus)
1460 °C 2650 °F
Melting Onset (Solidus)
1410 °C 2580 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
44 W/m-K 26 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.3 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.4 % IACS
Otherwise Unclassified Properties
Base Metal Price
2.4 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
1.5 kg CO2/kg material
Embodied Energy
20 MJ/kg 8.5 x 103 BTU/lb
Embodied Water
50 L/kg 6.0 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
110 MJ/m3
Resilience: Unit (Modulus of Resilience)
5860 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
57 points
Strength to Weight: Bending
39 points
Thermal Diffusivity
12 mm2/s
Thermal Shock Resistance
47 points
Alloy Composition
| Fe | 96.7 to 97.9 | |
| Mn | 0.7 to 1.0 | |
| Cr | 0.7 to 1.0 | |
| C | 0.56 to 0.64 | |
| Si | 0 to 0.4 | |
| Mo | 0.15 to 0.25 | |
| P | 0 to 0.025 | |
| S | 0 to 0.025 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
EN 10089: Hot rolled steels for quenched and tempered springs - Technical delivery conditions
Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005
Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015