EN 1.5681 (GX9Ni5) Cast Steel
EN 1.5681 steel is an alloy steel formulated for casting. Cited properties are appropriate for the quenched and tempered condition. 1.5681 is the EN numeric designation for this material. GX9Ni5 is the EN chemical designation.
It has a fairly high base cost among cast alloy steels. In addition, it has a moderately high electrical conductivity and a moderately high embodied energy.
The graph bars on the material properties cards below compare EN 1.5681 steel to: cast 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
190
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
20 %
Fatigue Strength
300 MPa 43 x 103 psi
Impact Strength: V-Notched Charpy
110 J 83 ft-lb
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
630 MPa 91 x 103 psi
Tensile Strength: Yield (Proof)
430 MPa 62 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
420 °C 780 °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
48 W/m-K 28 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.9 % IACS
Electrical Conductivity: Equal Weight (Specific)
9.0 % IACS
Otherwise Unclassified Properties
Base Metal Price
5.0 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
1.9 kg CO2/kg material
Embodied Energy
25 MJ/kg 11 x 103 BTU/lb
Embodied Water
55 L/kg 6.6 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
110 MJ/m3
Resilience: Unit (Modulus of Resilience)
490 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
22 points
Strength to Weight: Bending
21 points
Thermal Diffusivity
13 mm2/s
Thermal Shock Resistance
19 points
Alloy Composition
Among cast alloy steels, the composition of EN 1.5681 steel is notable for containing a comparatively high amount of nickel (Ni). Nickel is used to improve mechanical properties, and to make the alloy easier to heat treat.
| Fe | 92.9 to 94.9 | |
| Ni | 4.5 to 5.5 | |
| Mn | 0.5 to 0.8 | |
| Si | 0 to 0.6 | |
| C | 0.060 to 0.12 | |
| P | 0 to 0.020 | |
| S | 0 to 0.020 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
EN 10293: Steel castings - Steel castings for general engineering uses
ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996
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