UNS S33550 Stainless Steel
S33550 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 moderately high base cost and a moderately high embodied energy among wrought austenitic stainless steels.
The graph bars on the material properties cards below compare S33550 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
190
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
40 %
Fatigue Strength
270 MPa 39 x 103 psi
Poisson's Ratio
0.27
Rockwell B Hardness
82
Shear Modulus
79 GPa 11 x 106 psi
Shear Strength
470 MPa 68 x 103 psi
Tensile Strength: Ultimate (UTS)
680 MPa 99 x 103 psi
Tensile Strength: Yield (Proof)
310 MPa 45 x 103 psi
Thermal Properties
Latent Heat of Fusion
300 J/g
Maximum Temperature: Corrosion
470 °C 870 °F
Maximum Temperature: Mechanical
1100 °C 2010 °F
Melting Completion (Liquidus)
1400 °C 2560 °F
Melting Onset (Solidus)
1360 °C 2480 °F
Specific Heat Capacity
480 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
15 W/m-K 8.5 BTU/h-ft-°F
Thermal Expansion
16 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.1 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.4 % IACS
Otherwise Unclassified Properties
Base Metal Price
24 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
4.3 kg CO2/kg material
Embodied Energy
61 MJ/kg 26 x 103 BTU/lb
Embodied Water
190 L/kg 23 gal/lb
Common Calculations
PREN (Pitting Resistance)
30
Resilience: Ultimate (Unit Rupture Work)
220 MJ/m3
Resilience: Unit (Modulus of Resilience)
250 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
24 points
Strength to Weight: Bending
22 points
Thermal Diffusivity
3.9 mm2/s
Thermal Shock Resistance
15 points
Alloy Composition
Among wrought stainless steels, the composition of S33550 stainless steel is notable for including lanthanum (La) and cerium (Ce). Lanthanum is used to get better mechanical properties from heat treatment. Cerium is used to improve high temperature oxidation resistance.
| Fe | 48.8 to 58.2 | |
| Cr | 25 to 28 | |
| Ni | 16.5 to 20 | |
| Mn | 0 to 1.5 | |
| Si | 0 to 1.0 | |
| N | 0.18 to 0.25 | |
| Nb | 0.050 to 0.15 | |
| C | 0.040 to 0.1 | |
| La | 0.025 to 0.070 | |
| Ce | 0.025 to 0.070 | |
| 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 A240: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
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
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
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015