UNS N08801 (Alloy 801) Stainless Steel
N08801 stainless steel is a superaustenitic (highly alloyed) stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. N08801 is the UNS number for this material. Alloy 801 is the common industry name.
It has a moderately low base cost among wrought superaustenitic stainless steels. In addition, it has a fairly high tensile strength and a moderately low ductility.
The graph bars on the material properties cards below compare N08801 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 28 x 106 psi
Elongation at Break
34 %
Fatigue Strength
260 MPa 37 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
77 GPa 11 x 106 psi
Shear Strength
570 MPa 83 x 103 psi
Tensile Strength: Ultimate (UTS)
860 MPa 120 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
630 °C 1160 °F
Maximum Temperature: Mechanical
1090 °C 1990 °F
Melting Completion (Liquidus)
1390 °C 2530 °F
Melting Onset (Solidus)
1360 °C 2470 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
12 W/m-K 7.2 BTU/h-ft-°F
Thermal Expansion
16 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
1.7 % IACS
Electrical Conductivity: Equal Weight (Specific)
1.9 % IACS
Otherwise Unclassified Properties
Base Metal Price
30 % relative
Density
8.0 g/cm3 500 lb/ft3
Embodied Carbon
5.5 kg CO2/kg material
Embodied Energy
79 MJ/kg 34 x 103 BTU/lb
Embodied Water
200 L/kg 23 gal/lb
Common Calculations
PREN (Pitting Resistance)
21
Resilience: Ultimate (Unit Rupture Work)
220 MJ/m3
Resilience: Unit (Modulus of Resilience)
92 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
30 points
Strength to Weight: Bending
25 points
Thermal Diffusivity
3.3 mm2/s
Thermal Shock Resistance
20 points
Alloy Composition
Among wrought stainless steels, the composition of N08801 stainless steel is notable for including titanium (Ti) and containing a comparatively high amount of nickel (Ni). Titanium is used to broadly improve mechanical properties. 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 | 39.5 to 50.3 | |
| Ni | 30 to 34 | |
| Cr | 19 to 22 | |
| Ti | 0.75 to 1.5 | |
| Mn | 0 to 1.5 | |
| Si | 0 to 1.0 | |
| Cu | 0 to 0.5 | |
| C | 0 to 0.1 | |
| S | 0 to 0.015 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B407: Standard Specification for Nickel-Iron-Chromium Alloy Seamless Pipe and Tube
ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys, Joseph R. Davis (editor), 2000
Nickel Alloys, Ulrich Heubner (editor), 1998
Welding Metallurgy and Weldability of Stainless Steels, John C. Lippold and Damian J. Kotecki, 2005
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
ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994
Advances in Stainless Steels, Baldev Raj et al. (editors), 2010
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015