EN 1.4825 (GX25CrNiSi18-9) Cast Stainless Steel
EN 1.4825 stainless steel is an austenitic stainless steel formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. 1.4825 is the EN numeric designation for this material. GX25CrNiSi18-9 is the EN chemical designation.
It has a very low base cost among cast austenitic stainless steels. In addition, it has a moderately high electrical conductivity and a very low embodied energy.
The graph bars on the material properties cards below compare EN 1.4825 stainless steel to: cast austenitic 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
Brinell Hardness
150
Elastic (Young's, Tensile) Modulus
200 GPa 28 x 106 psi
Elongation at Break
17 %
Fatigue Strength
160 MPa 23 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
77 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
510 MPa 74 x 103 psi
Tensile Strength: Yield (Proof)
260 MPa 37 x 103 psi
Thermal Properties
Latent Heat of Fusion
300 J/g
Maximum Temperature: Corrosion
410 °C 770 °F
Maximum Temperature: Mechanical
900 °C 1650 °F
Melting Completion (Liquidus)
1410 °C 2570 °F
Melting Onset (Solidus)
1370 °C 2500 °F
Specific Heat Capacity
480 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
15 W/m-K 8.6 BTU/h-ft-°F
Thermal Expansion
16 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.3 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.7 % IACS
Otherwise Unclassified Properties
Base Metal Price
15 % relative
Density
7.7 g/cm3 480 lb/ft3
Embodied Carbon
3.1 kg CO2/kg material
Embodied Energy
43 MJ/kg 19 x 103 BTU/lb
Embodied Water
140 L/kg 17 gal/lb
Common Calculations
PREN (Pitting Resistance)
19
Resilience: Ultimate (Unit Rupture Work)
72 MJ/m3
Resilience: Unit (Modulus of Resilience)
170 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
18 points
Strength to Weight: Bending
18 points
Thermal Diffusivity
4.0 mm2/s
Thermal Shock Resistance
12 points
Alloy Composition
Among cast stainless steels, the composition of EN 1.4825 stainless steel is notable for containing a comparatively high amount of silicon (Si). Silicon content is typically governed by metallurgical processing concerns, but it can also be added for the purpose of improving oxidation resistance.
| Fe | 65.6 to 74.4 | |
| Cr | 17 to 19 | |
| Ni | 8.0 to 10 | |
| Si | 0.5 to 2.5 | |
| Mn | 0 to 2.0 | |
| C | 0.15 to 0.35 | |
| Mo | 0 to 0.5 | |
| P | 0 to 0.040 | |
| S | 0 to 0.030 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
EN 10295: Heat Resistant Steel Castings
Welding Metallurgy of Stainless Steels, Erich Folkhard et al., 2012
Corrosion of Austenitic Stainless Steels: Mechanism, Mitigation and Monitoring, H. S. Khatak and B. Raj (editors), 2002
Austenitic Stainless Steels: Microstructure and Mechanical Properties, P. Marshall, 1984
Corrosion of Stainless Steels, A. John Sedriks, 1996
Advances in Stainless Steels, Baldev Raj et al. (editors), 2010