EN 1.4911 (X8CrCoNiMo10-6) Stainless Steel
EN 1.4911 stainless steel is a martensitic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the quenched and tempered condition. 1.4911 is the EN numeric designation for this material. X8CrCoNiMo10-6 is the EN chemical designation.
It has the highest base cost among wrought martensitic stainless steels. In addition, it has a fairly high embodied energy and a moderately low ductility.
The graph bars on the material properties cards below compare EN 1.4911 stainless steel to: wrought martensitic stainless 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
Elastic (Young's, Tensile) Modulus
200 GPa 28 x 106 psi
Elongation at Break
11 %
Fatigue Strength
530 MPa 77 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
76 GPa 11 x 106 psi
Shear Strength
640 MPa 93 x 103 psi
Tensile Strength: Ultimate (UTS)
1070 MPa 160 x 103 psi
Tensile Strength: Yield (Proof)
970 MPa 140 x 103 psi
Thermal Properties
Latent Heat of Fusion
270 J/g
Maximum Temperature: Corrosion
430 °C 800 °F
Maximum Temperature: Mechanical
700 °C 1290 °F
Melting Completion (Liquidus)
1450 °C 2650 °F
Melting Onset (Solidus)
1410 °C 2570 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
20 W/m-K 12 BTU/h-ft-°F
Thermal Expansion
11 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.7 % IACS
Electrical Conductivity: Equal Weight (Specific)
3.0 % IACS
Otherwise Unclassified Properties
Base Metal Price
20 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
3.4 kg CO2/kg material
Embodied Energy
49 MJ/kg 21 x 103 BTU/lb
Embodied Water
130 L/kg 15 gal/lb
Common Calculations
PREN (Pitting Resistance)
14
Resilience: Ultimate (Unit Rupture Work)
120 MJ/m3
Resilience: Unit (Modulus of Resilience)
2410 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
38 points
Strength to Weight: Bending
30 points
Thermal Diffusivity
5.4 mm2/s
Thermal Shock Resistance
37 points
Alloy Composition
Among wrought stainless steels, the composition of EN 1.4911 stainless steel is notable for including cobalt (Co) and boron (B). Cobalt is used to improve mechanical strength at elevated temperatures. Boron is used to improve hardenability. It has a substantial effect when added in even tiny amounts. It can also facilitate sintering.
| Fe | 75.7 to 83.8 | |
| Cr | 9.8 to 11.2 | |
| Co | 5.0 to 7.0 | |
| Mn | 0.3 to 1.3 | |
| Mo | 0.5 to 1.0 | |
| Ni | 0.2 to 1.2 | |
| Si | 0.1 to 0.8 | |
| W | 0 to 0.7 | |
| Nb | 0.2 to 0.5 | |
| V | 0.1 to 0.4 | |
| C | 0.050 to 0.12 | |
| N | 0 to 0.035 | |
| P | 0 to 0.025 | |
| B | 0.0050 to 0.015 | |
| S | 0 to 0.015 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
EN 10302: Creep resisting steels, nickel and cobalt alloys
Machining of Stainless Steels and Super Alloys: Traditional and Nontraditional Techniques, Helmi A. Youssef, 2016
Creep-Resistant Steels, Fujio Abe et al. (editors), 2008
Welding Metallurgy and Weldability of Stainless Steels, John C. Lippold and Damian J. Kotecki, 2005
EN 10088-1: Stainless steels - Part 1: List of stainless steels
Corrosion of Stainless Steels, A. John Sedriks, 1996
Advances in Stainless Steels, Baldev Raj et al. (editors), 2010
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015