EN 1.7380 (10CrMo9-10) Chromium-Molybdenum Steel
EN 1.7380 steel is an alloy steel formulated for primary forming into wrought products. 1.7380 is the EN numeric designation for this material. 10CrMo9-10 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 1.7380 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 1.7380 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
160 to 170
Elastic (Young's, Tensile) Modulus
190 GPa 28 x 106 psi
Elongation at Break
19 to 20 %
Fatigue Strength
200 to 230 MPa 29 to 33 x 103 psi
Impact Strength: V-Notched Charpy
31 to 35 J 23 to 26 ft-lb
Poisson's Ratio
0.29
Shear Modulus
74 GPa 11 x 106 psi
Shear Strength
330 to 350 MPa 48 to 50 x 103 psi
Tensile Strength: Ultimate (UTS)
540 to 550 MPa 78 to 80 x 103 psi
Tensile Strength: Yield (Proof)
290 to 330 MPa 43 to 47 x 103 psi
Thermal Properties
Latent Heat of Fusion
260 J/g
Maximum Temperature: Mechanical
460 °C 860 °F
Melting Completion (Liquidus)
1470 °C 2670 °F
Melting Onset (Solidus)
1430 °C 2600 °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
3.8 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
1.8 kg CO2/kg material
Embodied Energy
23 MJ/kg 9.9 x 103 BTU/lb
Embodied Water
59 L/kg 7.0 gal/lb
Common Calculations
PREN (Pitting Resistance)
5.6
Resilience: Ultimate (Unit Rupture Work)
87 to 98 MJ/m3
Resilience: Unit (Modulus of Resilience)
230 to 280 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
19 to 20 points
Strength to Weight: Bending
19 points
Thermal Diffusivity
11 mm2/s
Thermal Shock Resistance
15 to 16 points
Alloy Composition
Among alloy steels, the composition of EN 1.7380 steel is notable for including nitrogen (N) and containing a comparatively high amount of chromium (Cr). Nitrogen has a substantial strengthening effect, but may contribute to strain aging unless the steel is deoxidized with aluminum. Chromium is used to improve corrosion resistance and most mechanical properties (particularly at higher temperatures).
| Fe | 94.6 to 96.6 | |
| Cr | 2.0 to 2.5 | |
| Mo | 0.9 to 1.1 | |
| Mn | 0.4 to 0.8 | |
| Si | 0 to 0.5 | |
| Cu | 0 to 0.3 | |
| C | 0.080 to 0.14 | |
| P | 0 to 0.020 | |
| N | 0 to 0.012 | |
| S | 0 to 0.010 |
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
EN 10216-2: Seamless steel tubes for pressure purposes - Technical delivery conditions - Part 2: Non-alloy and alloy steel tubes 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