EN 1.7707 (30CrMoV9) Chromium Steel
EN 1.7707 steel is an alloy steel formulated for primary forming into wrought products. Cited properties are appropriate for the quenched and tempered condition. 1.7707 is the EN numeric designation for this material. 30CrMoV9 is the EN chemical designation.
It has a fairly low thermal conductivity among EN wrought alloy steels. In addition, it has a fairly high embodied energy and a moderately high electrical conductivity.
The graph bars on the material properties cards below compare EN 1.7707 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
300
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
11 %
Fatigue Strength
500 MPa 72 x 103 psi
Impact Strength: V-Notched Charpy
31 J 23 ft-lb
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
600 MPa 88 x 103 psi
Tensile Strength: Ultimate (UTS)
1010 MPa 150 x 103 psi
Tensile Strength: Yield (Proof)
800 MPa 120 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
460 °C 850 °F
Melting Completion (Liquidus)
1460 °C 2660 °F
Melting Onset (Solidus)
1420 °C 2580 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
39 W/m-K 23 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.6 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.7 % IACS
Otherwise Unclassified Properties
Base Metal Price
3.3 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
1.9 kg CO2/kg material
Embodied Energy
27 MJ/kg 11 x 103 BTU/lb
Embodied Water
58 L/kg 7.0 gal/lb
Common Calculations
PREN (Pitting Resistance)
3.2
Resilience: Ultimate (Unit Rupture Work)
110 MJ/m3
Resilience: Unit (Modulus of Resilience)
1690 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
36 points
Strength to Weight: Bending
29 points
Thermal Diffusivity
11 mm2/s
Thermal Shock Resistance
29 points
Alloy Composition
Among alloy steels, the composition of EN 1.7707 steel is notable for containing a comparatively high amount of chromium (Cr) and including vanadium (V). Chromium is used to improve corrosion resistance and most mechanical properties (particularly at higher temperatures). Vanadium has a strong hardening effect, but this effect is particularly sensitive to the type of tempering.
| Fe | 94.7 to 96.8 | |
| Cr | 2.3 to 2.7 | |
| Mn | 0.4 to 0.7 | |
| C | 0.26 to 0.34 | |
| Ni | 0 to 0.6 | |
| Si | 0 to 0.4 | |
| Mo | 0.15 to 0.25 | |
| V | 0.1 to 0.2 | |
| P | 0 to 0.035 | |
| S | 0 to 0.035 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
EN 10250-3: Open die steel forgings for general engineering purposes - Part 3: Alloy special steels
Microstructure of Steels and Cast Irons, Madeleine Durand-Charre, 2004
ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996
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