Spheroidized (+AC) 1.7709 Steel
EN 1.7709 +AC steel is EN 1.7709 steel in the spheroidized condition. The graph bars on the material properties cards below compare EN 1.7709 +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)
650 MPa 95 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
440 °C 820 °F
Melting Completion (Liquidus)
1470 °C 2670 °F
Melting Onset (Solidus)
1420 °C 2600 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
33 W/m-K 19 BTU/h-ft-°F
Thermal Expansion
11 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.5 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.6 % IACS
Otherwise Unclassified Properties
Base Metal Price
3.4 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
2.3 kg CO2/kg material
Embodied Energy
32 MJ/kg 14 x 103 BTU/lb
Embodied Water
56 L/kg 6.7 gal/lb
Common Calculations
PREN (Pitting Resistance)
3.6
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
23 points
Strength to Weight: Bending
21 points
Thermal Diffusivity
8.9 mm2/s
Thermal Shock Resistance
22 points
Alloy Composition
| Fe | 95.2 to 97.5 | |
| Cr | 1.2 to 1.5 | |
| Mo | 0.55 to 0.8 | |
| Mn | 0.4 to 0.8 | |
| Ni | 0 to 0.6 | |
| V | 0.2 to 0.35 | |
| C | 0.17 to 0.25 | |
| Si | 0 to 0.4 | |
| S | 0 to 0.030 | |
| Al | 0 to 0.030 | |
| P | 0 to 0.025 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
EN 10269: Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties
Creep-Resistant Steels, Fujio Abe et al. (editors), 2008
Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005
Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015