EN 1.7703 (13CrMoV9-10) Chromium-Molybdenum Steel
EN 1.7703 steel is an alloy steel formulated for primary forming into wrought products. 1.7703 is the EN numeric designation for this material. 13CrMoV9-10 is the EN chemical designation.
It has a moderately high density among EN wrought alloy steels. In addition, it has a very high melting temperature and a fairly low thermal conductivity.
The properties of EN 1.7703 steel include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare EN 1.7703 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 to 210
Elastic (Young's, Tensile) Modulus
190 GPa 28 x 106 psi
Elongation at Break
20 %
Fatigue Strength
320 to 340 MPa 47 to 50 x 103 psi
Impact Strength: V-Notched Charpy
46 J 34 ft-lb
Poisson's Ratio
0.29
Shear Modulus
74 GPa 11 x 106 psi
Shear Strength
420 to 430 MPa 61 to 62 x 103 psi
Tensile Strength: Ultimate (UTS)
670 to 690 MPa 97 to 99 x 103 psi
Tensile Strength: Yield (Proof)
460 to 500 MPa 67 to 72 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
460 °C 860 °F
Melting Completion (Liquidus)
1470 °C 2680 °F
Melting Onset (Solidus)
1430 °C 2610 °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
4.2 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
2.5 kg CO2/kg material
Embodied Energy
35 MJ/kg 15 x 103 BTU/lb
Embodied Water
61 L/kg 7.2 gal/lb
Common Calculations
PREN (Pitting Resistance)
5.6
Resilience: Ultimate (Unit Rupture Work)
120 to 130 MJ/m3
Resilience: Unit (Modulus of Resilience)
570 to 650 kJ/m3
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
11 mm2/s
Thermal Shock Resistance
19 to 20 points
Alloy Composition
Among alloy steels, the composition of EN 1.7703 steel is notable for including niobium (Nb) and titanium (Ti). Niobium is primarily used to improve yield strength. Titanium is used to broadly improve mechanical properties.
| Fe | 94.6 to 96.4 | |
| Cr | 2.0 to 2.5 | |
| Mo | 0.9 to 1.1 | |
| Mn | 0.3 to 0.6 | |
| V | 0.25 to 0.35 | |
| C | 0.11 to 0.15 | |
| Ni | 0 to 0.25 | |
| Cu | 0 to 0.2 | |
| Si | 0 to 0.1 | |
| Nb | 0 to 0.070 | |
| Ti | 0 to 0.030 | |
| P | 0 to 0.015 | |
| N | 0 to 0.012 | |
| S | 0 to 0.0050 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
EN 10028-2: Flat products made of steels for pressure purposes - Part 2: Non-alloy and alloy steels with specified elevated temperature properties
Welding Metallurgy, 2nd ed., Sindo Kou, 2003
Creep-Resistant Steels, Fujio Abe et al. (editors), 2008
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
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