EN 1.7375 (12CrMo9-10) Chromium-Molybdenum Steel
EN 1.7375 steel is an alloy steel formulated for primary forming into wrought products. Cited properties are appropriate for the normalized and tempered condition. 1.7375 is the EN numeric designation for this material. 12CrMo9-10 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 graph bars on the material properties cards below compare EN 1.7375 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
180
Elastic (Young's, Tensile) Modulus
190 GPa 28 x 106 psi
Elongation at Break
20 %
Fatigue Strength
270 MPa 40 x 103 psi
Impact Strength: V-Notched Charpy
80 J 59 ft-lb
Poisson's Ratio
0.29
Shear Modulus
74 GPa 11 x 106 psi
Shear Strength
380 MPa 56 x 103 psi
Tensile Strength: Ultimate (UTS)
620 MPa 89 x 103 psi
Tensile Strength: Yield (Proof)
400 MPa 58 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 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
3.9 % 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 7.1 gal/lb
Common Calculations
PREN (Pitting Resistance)
5.6
Resilience: Ultimate (Unit Rupture Work)
110 MJ/m3
Resilience: Unit (Modulus of Resilience)
420 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
22 points
Strength to Weight: Bending
20 points
Thermal Diffusivity
11 mm2/s
Thermal Shock Resistance
18 points
Alloy Composition
Among alloy steels, the composition of EN 1.7375 steel is notable for including nitrogen (N) and aluminum (Al). Nitrogen has a substantial strengthening effect, but may contribute to strain aging unless the steel is deoxidized with aluminum. Aluminum is used to control grain size and to deoxidize. Deoxidizing is required to control the effects of some other alloying elements.
| Fe | 94.5 to 96.7 | |
| Cr | 2.0 to 2.5 | |
| Mo | 0.9 to 1.1 | |
| Mn | 0.3 to 0.8 | |
| Si | 0 to 0.3 | |
| Ni | 0 to 0.3 | |
| C | 0.1 to 0.15 | |
| Cu | 0 to 0.25 | |
| Al | 0.010 to 0.040 | |
| P | 0 to 0.015 | |
| 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
Creep-Resistant Steels, Fujio Abe et al. (editors), 2008
Microstructure of Steels and Cast Irons, Madeleine Durand-Charre, 2004
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