UNS N08320 Stainless Steel
N08320 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.
It has a very low base cost among wrought superaustenitic stainless steels. In addition, it has the lowest embodied energy and a moderately low tensile strength.
The graph bars on the material properties cards below compare N08320 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
Brinell Hardness
190
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
40 %
Fatigue Strength
190 MPa 27 x 103 psi
Poisson's Ratio
0.28
Rockwell B Hardness
84
Shear Modulus
78 GPa 11 x 106 psi
Shear Strength
400 MPa 58 x 103 psi
Tensile Strength: Ultimate (UTS)
580 MPa 85 x 103 psi
Tensile Strength: Yield (Proof)
220 MPa 32 x 103 psi
Thermal Properties
Latent Heat of Fusion
300 J/g
Maximum Temperature: Corrosion
430 °C 810 °F
Maximum Temperature: Mechanical
1100 °C 2010 °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 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)
2.0 % IACS
Otherwise Unclassified Properties
Base Metal Price
28 % relative
Density
8.0 g/cm3 500 lb/ft3
Embodied Carbon
4.9 kg CO2/kg material
Embodied Energy
69 MJ/kg 30 x 103 BTU/lb
Embodied Water
200 L/kg 24 gal/lb
Common Calculations
PREN (Pitting Resistance)
22
Resilience: Ultimate (Unit Rupture Work)
180 MJ/m3
Resilience: Unit (Modulus of Resilience)
120 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
20 points
Strength to Weight: Bending
20 points
Thermal Diffusivity
3.3 mm2/s
Thermal Shock Resistance
13 points
Alloy Composition
Among wrought stainless steels, the composition of N08320 stainless steel is notable for containing comparatively high amounts of manganese (Mn) and nickel (Ni). Manganese is used to improve ductility at elevated temperatures. It also permits a higher nitrogen content than would otherwise be possible. 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 | 40.4 to 50 | |
| Ni | 25 to 27 | |
| Cr | 21 to 23 | |
| Mn | 0 to 2.5 | |
| Si | 0 to 1.0 | |
| C | 0 to 0.050 | |
| 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
ASTM B620: Standard Specification for Nickel-Iron-Chromium-Molybdenum Alloy (UNS N08320) Plate, Sheet, and Strip
ASTM B621: Standard Specification for Nickel-Iron-Chromium-Molybdenum Alloy (UNS N08320) Rod
ASTM B619: Standard Specification for Welded Nickel and Nickel-Cobalt Alloy Pipe
ASTM B626: Standard Specification for Welded Nickel and Nickel-Cobalt Alloy Tube
ASTM B622: Standard Specification for Seamless Nickel and Nickel-Cobalt Alloy Pipe and Tube
Nickel Alloys, Ulrich Heubner (editor), 1998
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
ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994