EN 1.4424 (X2CrNiMoSi18-5-3) Stainless Steel
EN 1.4424 stainless steel is a duplex stainless steel formulated for primary forming into wrought products. 1.4424 is the EN numeric designation for this material. X2CrNiMoSi18-5-3 is the EN chemical designation.
It has a fairly low thermal conductivity among the wrought duplex stainless steels in the database.
The properties of EN 1.4424 stainless 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 1.4424 stainless steel to: wrought duplex 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
230
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
28 %
Fatigue Strength
350 to 370 MPa 51 to 53 x 103 psi
Impact Strength: V-Notched Charpy
90 to 91 J 67 ft-lb
Poisson's Ratio
0.28
Shear Modulus
78 GPa 11 x 106 psi
Shear Strength
520 MPa 75 x 103 psi
Tensile Strength: Ultimate (UTS)
800 MPa 120 x 103 psi
Tensile Strength: Yield (Proof)
480 to 500 MPa 70 to 73 x 103 psi
Thermal Properties
Latent Heat of Fusion
310 J/g
Maximum Temperature: Corrosion
420 °C 780 °F
Maximum Temperature: Mechanical
960 °C 1750 °F
Melting Completion (Liquidus)
1430 °C 2610 °F
Melting Onset (Solidus)
1390 °C 2530 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
13 W/m-K 7.5 BTU/h-ft-°F
Thermal Expansion
12 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.2 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.5 % IACS
Otherwise Unclassified Properties
Base Metal Price
15 % relative
Density
7.7 g/cm3 480 lb/ft3
Embodied Carbon
3.4 kg CO2/kg material
Embodied Energy
46 MJ/kg 20 x 103 BTU/lb
Embodied Water
140 L/kg 17 gal/lb
Common Calculations
PREN (Pitting Resistance)
29
Resilience: Ultimate (Unit Rupture Work)
190 to 200 MJ/m3
Resilience: Unit (Modulus of Resilience)
580 to 640 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
29 points
Strength to Weight: Bending
25 points
Thermal Diffusivity
3.5 mm2/s
Thermal Shock Resistance
23 points
Alloy Composition
Among wrought stainless steels, the composition of EN 1.4424 stainless steel is notable for containing comparatively high amounts of silicon (Si) and manganese (Mn). Silicon content is typically governed by metallurgical processing concerns, but it can also be added for the purpose of improving oxidation resistance. Manganese is used to improve ductility at elevated temperatures. It also permits a higher nitrogen content than would otherwise be possible.
| Fe | 68.6 to 72.4 | |
| Cr | 18 to 19 | |
| Ni | 4.5 to 5.2 | |
| Mo | 2.5 to 3.0 | |
| Si | 1.4 to 2.0 | |
| Mn | 1.2 to 2.0 | |
| N | 0.050 to 0.1 | |
| P | 0 to 0.035 | |
| C | 0 to 0.030 | |
| S | 0 to 0.015 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
Duplex Stainless Steels, Iris Alvarez-Armas and Suzanne Degallaix-Moreuil (editors), 2009
Duplex Stainless Steels: Microstructure, Properties and Applications, Robert N. Gunn (editor), 1997
EN 10088-2: Stainless steels - Part 2: Technical delivery conditions for sheet/plate and strip of corrosion resisting steels for general purposes
EN 10088-3: Stainless steels - Part 3: Technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products of corrosion resisting steels for general purposes
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