UNS S40945 Stainless Steel
S40945 stainless steel is a ferritic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition.
It has a fairly low tensile strength among wrought ferritic stainless steels. In addition, it has a moderately high ductility and a moderately high thermal conductivity.
The graph bars on the material properties cards below compare S40945 stainless steel to: wrought ferritic 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
160
Elastic (Young's, Tensile) Modulus
190 GPa 28 x 106 psi
Elongation at Break
25 %
Fatigue Strength
160 MPa 23 x 103 psi
Poisson's Ratio
0.28
Rockwell B Hardness
69
Shear Modulus
75 GPa 11 x 106 psi
Shear Strength
270 MPa 39 x 103 psi
Tensile Strength: Ultimate (UTS)
430 MPa 62 x 103 psi
Tensile Strength: Yield (Proof)
230 MPa 34 x 103 psi
Thermal Properties
Latent Heat of Fusion
270 J/g
Maximum Temperature: Corrosion
450 °C 840 °F
Maximum Temperature: Mechanical
710 °C 1300 °F
Melting Completion (Liquidus)
1450 °C 2640 °F
Melting Onset (Solidus)
1410 °C 2560 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
26 W/m-K 15 BTU/h-ft-°F
Thermal Expansion
10 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.9 % IACS
Electrical Conductivity: Equal Weight (Specific)
3.3 % IACS
Otherwise Unclassified Properties
Base Metal Price
8.0 % relative
Density
7.8 g/cm3 480 lb/ft3
Embodied Carbon
2.2 kg CO2/kg material
Embodied Energy
31 MJ/kg 13 x 103 BTU/lb
Embodied Water
94 L/kg 11 gal/lb
Common Calculations
PREN (Pitting Resistance)
11
Resilience: Ultimate (Unit Rupture Work)
89 MJ/m3
Resilience: Unit (Modulus of Resilience)
140 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
15 points
Strength to Weight: Bending
16 points
Thermal Diffusivity
6.9 mm2/s
Thermal Shock Resistance
15 points
Alloy Composition
Among wrought stainless steels, the composition of S40945 stainless steel is notable for including titanium (Ti) and niobium (Nb). Titanium is used to broadly improve mechanical properties. Niobium is primarily used to improve yield strength, particularly at elevated temperatures.
| Fe | 85.1 to 89.3 | |
| Cr | 10.5 to 11.7 | |
| Mn | 0 to 1.0 | |
| Si | 0 to 1.0 | |
| Nb | 0.18 to 0.4 | |
| Ni | 0 to 0.5 | |
| Ti | 0.050 to 0.2 | |
| P | 0 to 0.040 | |
| C | 0 to 0.030 | |
| S | 0 to 0.030 | |
| N | 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
ASTM A959: Standard Guide for Specifying Harmonized Standard Grade Compositions for Wrought Stainless Steels
Corrosion of Stainless Steels, A. John Sedriks, 1996
ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994
Advances in Stainless Steels, Baldev Raj et al. (editors), 2010