EN 1.7338 (10CrMo5-5) Chromium-Molybdenum Steel
EN 1.7338 steel is an alloy steel formulated for primary forming into wrought products. Cited properties are appropriate for the normalized and tempered condition. 1.7338 is the EN numeric designation for this material. 10CrMo5-5 is the EN chemical designation.
It has a very low tensile strength among EN wrought alloy steels. In addition, it has a moderately low thermal conductivity and a moderately high base cost.
The graph bars on the material properties cards below compare EN 1.7338 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
150
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
23 %
Fatigue Strength
220 MPa 31 x 103 psi
Impact Strength: V-Notched Charpy
38 J 28 ft-lb
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
310 MPa 45 x 103 psi
Tensile Strength: Ultimate (UTS)
490 MPa 70 x 103 psi
Tensile Strength: Yield (Proof)
300 MPa 44 x 103 psi
Thermal Properties
Latent Heat of Fusion
260 J/g
Maximum Temperature: Mechanical
430 °C 810 °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
40 W/m-K 23 BTU/h-ft-°F
Thermal Expansion
13 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
3.1 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
1.6 kg CO2/kg material
Embodied Energy
21 MJ/kg 9.2 x 103 BTU/lb
Embodied Water
53 L/kg 6.4 gal/lb
Common Calculations
PREN (Pitting Resistance)
3.1
Resilience: Ultimate (Unit Rupture Work)
97 MJ/m3
Resilience: Unit (Modulus of Resilience)
240 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
17 points
Strength to Weight: Bending
18 points
Thermal Diffusivity
11 mm2/s
Thermal Shock Resistance
14 points
Alloy Composition
Among alloy steels, the composition of EN 1.7338 steel is notable for including aluminum (Al) and copper (Cu). Aluminum is used to control grain size and to deoxidize. Deoxidizing is required to control the effects of some other alloying elements. Copper is used to improve corrosion resistance, and to add at least some degree of precipitation hardenability.
| Fe | 95.4 to 97.8 | |
| Cr | 1.0 to 1.5 | |
| Si | 0.5 to 1.0 | |
| Mo | 0.45 to 0.65 | |
| Mn | 0.3 to 0.6 | |
| Ni | 0 to 0.3 | |
| Cu | 0 to 0.3 | |
| C | 0 to 0.15 | |
| Al | 0 to 0.040 | |
| P | 0 to 0.025 | |
| S | 0 to 0.010 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
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
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
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