AISI 445 (S44500) Stainless Steel
AISI 445 stainless steel is a ferritic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. 445 is the AISI designation for this material. S44500 is the UNS number.
It has a moderately high ductility among the wrought ferritic stainless steels in the database.
The graph bars on the material properties cards below compare AISI 445 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
200 GPa 29 x 106 psi
Elongation at Break
25 %
Fatigue Strength
160 MPa 23 x 103 psi
Poisson's Ratio
0.28
Rockwell B Hardness
71
Shear Modulus
78 GPa 11 x 106 psi
Shear Strength
310 MPa 44 x 103 psi
Tensile Strength: Ultimate (UTS)
480 MPa 69 x 103 psi
Tensile Strength: Yield (Proof)
230 MPa 34 x 103 psi
Thermal Properties
Latent Heat of Fusion
290 J/g
Maximum Temperature: Corrosion
480 °C 890 °F
Maximum Temperature: Mechanical
950 °C 1740 °F
Melting Completion (Liquidus)
1440 °C 2620 °F
Melting Onset (Solidus)
1390 °C 2540 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
21 W/m-K 12 BTU/h-ft-°F
Thermal Expansion
11 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.6 % IACS
Electrical Conductivity: Equal Weight (Specific)
3.0 % IACS
Otherwise Unclassified Properties
Base Metal Price
12 % relative
Density
7.7 g/cm3 480 lb/ft3
Embodied Carbon
2.6 kg CO2/kg material
Embodied Energy
38 MJ/kg 16 x 103 BTU/lb
Embodied Water
130 L/kg 16 gal/lb
Common Calculations
PREN (Pitting Resistance)
20
Resilience: Ultimate (Unit Rupture Work)
98 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
17 points
Strength to Weight: Bending
18 points
Thermal Diffusivity
5.6 mm2/s
Thermal Shock Resistance
16 points
Alloy Composition
Among wrought stainless steels, the composition of AISI 445 stainless steel is notable for including niobium (Nb) and copper (Cu). Niobium is primarily used to improve yield strength, particularly at elevated temperatures. Copper is used to improve resistance to acids, and to improve formability.
| Fe | 74.9 to 80.7 | |
| Cr | 19 to 21 | |
| Mn | 0 to 1.0 | |
| Si | 0 to 1.0 | |
| Cu | 0.3 to 0.6 | |
| Nb | 0 to 0.8 | |
| Ni | 0 to 0.6 | |
| P | 0 to 0.040 | |
| N | 0 to 0.030 | |
| C | 0 to 0.020 | |
| S | 0 to 0.012 |
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
Advanced Materials in Automotive Engineering, Jason Rowe (editor), 2012
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
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015