EN 1.7386 (X11CrMo9-1) High-Chromium Steel
EN 1.7386 steel is an alloy steel formulated for primary forming into wrought products. 1.7386 is the EN numeric designation for this material. X11CrMo9-1 is the EN chemical designation.
It has a very low thermal conductivity among EN wrought alloy steels. In addition, it has a very high electrical conductivity and a very high base cost.
The properties of EN 1.7386 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 1.7386 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
170 to 200
Elastic (Young's, Tensile) Modulus
190 GPa 28 x 106 psi
Elongation at Break
18 to 21 %
Fatigue Strength
170 to 290 MPa 24 to 43 x 103 psi
Impact Strength: V-Notched Charpy
38 J 28 ft-lb
Poisson's Ratio
0.28
Shear Modulus
75 GPa 11 x 106 psi
Shear Strength
340 to 410 MPa 50 to 60 x 103 psi
Tensile Strength: Ultimate (UTS)
550 to 670 MPa 80 to 96 x 103 psi
Tensile Strength: Yield (Proof)
240 to 440 MPa 35 to 63 x 103 psi
Thermal Properties
Latent Heat of Fusion
270 J/g
Maximum Temperature: Mechanical
600 °C 1110 °F
Melting Completion (Liquidus)
1450 °C 2650 °F
Melting Onset (Solidus)
1410 °C 2570 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
26 W/m-K 15 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
9.0 % IACS
Electrical Conductivity: Equal Weight (Specific)
10 % IACS
Otherwise Unclassified Properties
Base Metal Price
6.5 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
2.0 kg CO2/kg material
Embodied Energy
28 MJ/kg 12 x 103 BTU/lb
Embodied Water
88 L/kg 10 gal/lb
Common Calculations
PREN (Pitting Resistance)
12
Resilience: Ultimate (Unit Rupture Work)
92 to 110 MJ/m3
Resilience: Unit (Modulus of Resilience)
150 to 490 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
20 to 24 points
Strength to Weight: Bending
19 to 22 points
Thermal Diffusivity
6.9 mm2/s
Thermal Shock Resistance
15 to 18 points
Alloy Composition
Among alloy steels, the composition of EN 1.7386 steel is notable for containing a comparatively high amount of chromium (Cr) and including aluminum (Al). Chromium is used to improve corrosion resistance and most mechanical properties (particularly at higher temperatures). Aluminum is used to control grain size and to deoxidize. Deoxidizing is required to control the effects of some other alloying elements.
| Fe | 86.8 to 90.5 | |
| Cr | 8.0 to 10 | |
| Mo | 0.9 to 1.1 | |
| Si | 0.25 to 1.0 | |
| Mn | 0.3 to 0.6 | |
| Cu | 0 to 0.3 | |
| C | 0.080 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
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