UNS S20431 Stainless Steel
S20431 stainless steel is an austenitic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition.
It has a fairly low embodied energy among wrought austenitic stainless steels. In addition, it has a moderately low base cost and a moderately high ductility.
The graph bars on the material properties cards below compare S20431 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
210
Elastic (Young's, Tensile) Modulus
200 GPa 28 x 106 psi
Elongation at Break
46 %
Fatigue Strength
320 MPa 47 x 103 psi
Poisson's Ratio
0.28
Rockwell B Hardness
86
Shear Modulus
76 GPa 11 x 106 psi
Shear Strength
500 MPa 72 x 103 psi
Tensile Strength: Ultimate (UTS)
710 MPa 100 x 103 psi
Tensile Strength: Yield (Proof)
350 MPa 50 x 103 psi
Thermal Properties
Latent Heat of Fusion
280 J/g
Maximum Temperature: Corrosion
410 °C 770 °F
Maximum Temperature: Mechanical
890 °C 1640 °F
Melting Completion (Liquidus)
1400 °C 2560 °F
Melting Onset (Solidus)
1360 °C 2480 °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
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.4 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.8 % IACS
Otherwise Unclassified Properties
Base Metal Price
12 % relative
Density
7.7 g/cm3 480 lb/ft3
Embodied Carbon
2.5 kg CO2/kg material
Embodied Energy
36 MJ/kg 16 x 103 BTU/lb
Embodied Water
140 L/kg 17 gal/lb
Common Calculations
PREN (Pitting Resistance)
20
Resilience: Ultimate (Unit Rupture Work)
270 MJ/m3
Resilience: Unit (Modulus of Resilience)
310 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
25 points
Strength to Weight: Bending
23 points
Thermal Diffusivity
4.0 mm2/s
Thermal Shock Resistance
15 points
Alloy Composition
Among wrought stainless steels, the composition of S20431 stainless steel is notable for containing a comparatively high amount of manganese (Mn). Manganese is used to improve ductility at elevated temperatures. It also permits a higher nitrogen content than would otherwise be possible.
| Fe | 66.1 to 74.4 | |
| Cr | 17 to 18 | |
| Mn | 5.0 to 7.0 | |
| Ni | 2.0 to 4.0 | |
| Cu | 1.5 to 3.5 | |
| Si | 0 to 1.0 | |
| N | 0.1 to 0.25 | |
| C | 0 to 0.12 | |
| P | 0 to 0.045 | |
| S | 0 to 0.030 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A240: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
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
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
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