UNS N08925 Stainless Steel
N08925 stainless steel is a superaustenitic (highly alloyed) stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition.
It has a moderately high thermal conductivity and a moderately high ductility among wrought superaustenitic stainless steels.
The graph bars on the material properties cards below compare N08925 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 30 x 106 psi
Elongation at Break
45 %
Fatigue Strength
310 MPa 45 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
80 GPa 12 x 106 psi
Shear Strength
470 MPa 69 x 103 psi
Tensile Strength: Ultimate (UTS)
680 MPa 98 x 103 psi
Tensile Strength: Yield (Proof)
340 MPa 49 x 103 psi
Thermal Properties
Latent Heat of Fusion
300 J/g
Maximum Temperature: Corrosion
420 °C 800 °F
Maximum Temperature: Mechanical
1100 °C 2010 °F
Melting Completion (Liquidus)
1460 °C 2660 °F
Melting Onset (Solidus)
1410 °C 2570 °F
Specific Heat Capacity
460 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
13 W/m-K 7.6 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
33 % relative
Density
8.1 g/cm3 510 lb/ft3
Embodied Carbon
6.2 kg CO2/kg material
Embodied Energy
84 MJ/kg 36 x 103 BTU/lb
Embodied Water
200 L/kg 24 gal/lb
Common Calculations
PREN (Pitting Resistance)
44
Resilience: Ultimate (Unit Rupture Work)
250 MJ/m3
Resilience: Unit (Modulus of Resilience)
280 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
23 points
Strength to Weight: Bending
21 points
Thermal Diffusivity
3.5 mm2/s
Thermal Shock Resistance
15 points
Alloy Composition
Among wrought stainless steels, the composition of N08925 stainless steel is notable for containing a comparatively high amount of nickel (Ni) and including copper (Cu). Nickel is primarily used to achieve a specific microstructure. In addition, it has a beneficial effect on mechanical properties and certain types of corrosion. Copper is used to improve resistance to acids, and to improve formability.
| Fe | 42.7 to 50.1 | |
| Ni | 24 to 26 | |
| Cr | 19 to 21 | |
| Mo | 6.0 to 7.0 | |
| Cu | 0.8 to 1.5 | |
| Mn | 0 to 1.0 | |
| Si | 0 to 0.5 | |
| N | 0.1 to 0.2 | |
| P | 0 to 0.045 | |
| S | 0 to 0.030 | |
| C | 0 to 0.020 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B673: Standard Specification for UNS N08904, UNS N08925, and UNS N08926 Welded Pipe
ASTM B674: Standard Specification for UNS N08904, UNS N08925, and UNS N08926 Welded Tube
ASTM B677: Standard Specification for UNS N08904, UNS N08925, and UNS N08926 Seamless Pipe and Tube
ASTM B649: Standard Specification for Ni-Fe-Cr-Mo-Cu Low-Carbon Alloy (UNS N08904), Ni-Fe-Cr-Mo-Cu-N Low-Carbon Alloys (UNS N08925, UNS N08031, and UNS N08926), and Cr-Ni-Fe-N Low-Carbon Alloy (UNS R20033) Bar and Wire
Nickel Alloys, Ulrich Heubner (editor), 1998
ASTM A240: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
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