EN 1.4959 (X8NiCrAlTi32-21) Stainless Steel
EN 1.4959 stainless steel is a superaustenitic (highly alloyed) stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the solution annealed (AT) condition. 1.4959 is the EN numeric designation for this material. X8NiCrAlTi32-21 is the EN chemical designation.
It has a moderately low embodied energy and a moderately low base cost among wrought superaustenitic stainless steels.
The graph bars on the material properties cards below compare EN 1.4959 stainless steel to: wrought superaustenitic 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 29 x 106 psi
Elongation at Break
40 %
Fatigue Strength
170 MPa 24 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
77 GPa 11 x 106 psi
Shear Strength
430 MPa 62 x 103 psi
Tensile Strength: Ultimate (UTS)
630 MPa 91 x 103 psi
Tensile Strength: Yield (Proof)
190 MPa 28 x 103 psi
Thermal Properties
Latent Heat of Fusion
300 J/g
Maximum Temperature: Corrosion
510 °C 940 °F
Maximum Temperature: Mechanical
1090 °C 1990 °F
Melting Completion (Liquidus)
1400 °C 2550 °F
Melting Onset (Solidus)
1350 °C 2470 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
12 W/m-K 6.9 BTU/h-ft-°F
Thermal Expansion
15 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
1.7 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.0 % IACS
Otherwise Unclassified Properties
Base Metal Price
31 % relative
Density
8.0 g/cm3 500 lb/ft3
Embodied Carbon
5.4 kg CO2/kg material
Embodied Energy
76 MJ/kg 33 x 103 BTU/lb
Embodied Water
200 L/kg 24 gal/lb
Common Calculations
PREN (Pitting Resistance)
21
Resilience: Ultimate (Unit Rupture Work)
190 MJ/m3
Resilience: Unit (Modulus of Resilience)
96 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
22 points
Strength to Weight: Bending
20 points
Thermal Diffusivity
3.2 mm2/s
Thermal Shock Resistance
15 points
Alloy Composition
Among wrought stainless steels, the composition of EN 1.4959 stainless steel is notable for including cobalt (Co) and aluminum (Al). Cobalt is used to improve mechanical strength at elevated temperatures. Aluminum is used to improve oxidation resistance. It can also enhance the effects of heat treatment.
| Fe | 39.4 to 50.5 | |
| Ni | 30 to 34 | |
| Cr | 19 to 22 | |
| Mn | 0 to 1.5 | |
| Al | 0.25 to 0.65 | |
| Ti | 0.25 to 0.65 | |
| Si | 0 to 0.7 | |
| Co | 0 to 0.5 | |
| Cu | 0 to 0.5 | |
| C | 0.050 to 0.1 | |
| N | 0 to 0.030 | |
| P | 0 to 0.015 | |
| S | 0 to 0.010 |
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
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