Spheroidized (+AC) 1.7240 Steel
EN 1.7240 +AC steel is EN 1.7240 steel in the spheroidized condition. It has the lowest strength compared to the other variants of EN 1.7240 steel. The graph bars on the material properties cards below compare EN 1.7240 +AC 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
200
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
670 MPa 97 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
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
24 points
Strength to Weight: Bending
22 points
Thermal Diffusivity
12 mm2/s
Thermal Shock Resistance
20 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