EN 1.4318 (X2CrNiN18-7) Stainless Steel
EN 1.4318 stainless steel is an austenitic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the solution annealed (AT) condition. 1.4318 is the EN numeric designation for this material. X2CrNiN18-7 is the EN chemical designation.
It has a moderately low embodied energy among wrought austenitic stainless steels. In addition, it has a moderately low base cost and a moderately high tensile strength.
The graph bars on the material properties cards below compare EN 1.4318 stainless steel to: wrought 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
230
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
44 %
Fatigue Strength
340 MPa 50 x 103 psi
Impact Strength: V-Notched Charpy
85 J 63 ft-lb
Poisson's Ratio
0.28
Shear Modulus
77 GPa 11 x 106 psi
Shear Strength
520 MPa 75 x 103 psi
Tensile Strength: Ultimate (UTS)
740 MPa 110 x 103 psi
Tensile Strength: Yield (Proof)
380 MPa 55 x 103 psi
Thermal Properties
Latent Heat of Fusion
290 J/g
Maximum Temperature: Corrosion
410 °C 780 °F
Maximum Temperature: Mechanical
910 °C 1670 °F
Melting Completion (Liquidus)
1430 °C 2600 °F
Melting Onset (Solidus)
1380 °C 2520 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
15 W/m-K 8.7 BTU/h-ft-°F
Thermal Expansion
16 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.4 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.7 % IACS
Otherwise Unclassified Properties
Base Metal Price
13 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
2.8 kg CO2/kg material
Embodied Energy
39 MJ/kg 17 x 103 BTU/lb
Embodied Water
130 L/kg 16 gal/lb
Common Calculations
PREN (Pitting Resistance)
20
Resilience: Ultimate (Unit Rupture Work)
280 MJ/m3
Resilience: Unit (Modulus of Resilience)
360 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
27 points
Strength to Weight: Bending
23 points
Thermal Diffusivity
4.0 mm2/s
Thermal Shock Resistance
17 points
Alloy Composition
Among wrought stainless steels, the composition of EN 1.4318 stainless steel is notable for containing comparatively high amounts of chromium (Cr) and nickel (Ni). Chromium is the defining alloying element of stainless steel. Higher chromium content imparts additional corrosion resistance. Nickel is primarily used to achieve a specific microstructure. In addition, it has a beneficial effect on mechanical properties and certain types of corrosion.
| Fe | 70.2 to 77.4 | |
| Cr | 16.5 to 18.5 | |
| Ni | 6.0 to 8.0 | |
| Mn | 0 to 2.0 | |
| Si | 0 to 1.0 | |
| N | 0.1 to 0.2 | |
| P | 0 to 0.045 | |
| 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
EN 10088-2: Stainless steels - Part 2: Technical delivery conditions for sheet/plate and strip of corrosion resisting steels for general purposes
EN 10088-1: Stainless steels - Part 1: List of stainless steels
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
Advances in Stainless Steels, Baldev Raj et al. (editors), 2010