AISI 446 (S44600) Stainless Steel
AISI 446 stainless steel is a ferritic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. 446 is the AISI designation for this material. S44600 is the UNS number. Additionally, the AFNOR (French) designation is Z10C24.
This material is well established: the Further Reading section below cites a number of published standards, and that list is not necessarily exhaustive.
It has a fairly low electrical conductivity among wrought ferritic stainless steels. In addition, it has a moderately low thermal conductivity and a moderately high tensile strength.
The graph bars on the material properties cards below compare AISI 446 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
190
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
23 %
Fatigue Strength
200 MPa 29 x 103 psi
Poisson's Ratio
0.27
Reduction in Area
50 %
Rockwell B Hardness
84
Shear Modulus
79 GPa 11 x 106 psi
Shear Strength
360 MPa 52 x 103 psi
Tensile Strength: Ultimate (UTS)
570 MPa 83 x 103 psi
Tensile Strength: Yield (Proof)
300 MPa 44 x 103 psi
Thermal Properties
Latent Heat of Fusion
290 J/g
Maximum Temperature: Corrosion
440 °C 830 °F
Maximum Temperature: Mechanical
1180 °C 2150 °F
Melting Completion (Liquidus)
1510 °C 2750 °F
Melting Onset (Solidus)
1430 °C 2600 °F
Specific Heat Capacity
490 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
17 W/m-K 9.9 BTU/h-ft-°F
Thermal Expansion
11 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
1.9 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.3 % IACS
Otherwise Unclassified Properties
Base Metal Price
12 % relative
Calomel Potential
-230 mV
Density
7.7 g/cm3 480 lb/ft3
Embodied Carbon
2.4 kg CO2/kg material
Embodied Energy
35 MJ/kg 15 x 103 BTU/lb
Embodied Water
150 L/kg 18 gal/lb
Common Calculations
PREN (Pitting Resistance)
27
Resilience: Ultimate (Unit Rupture Work)
110 MJ/m3
Resilience: Unit (Modulus of Resilience)
230 kJ/m3
Stiffness to Weight: Axial
15 points
Stiffness to Weight: Bending
26 points
Strength to Weight: Axial
21 points
Strength to Weight: Bending
20 points
Thermal Diffusivity
4.6 mm2/s
Thermal Shock Resistance
19 points
Alloy Composition
Among wrought stainless steels, the composition of AISI 446 stainless steel is notable for containing a comparatively high amount of chromium (Cr). Chromium is the defining alloying element of stainless steel. Higher chromium content imparts additional corrosion resistance.
| Fe | 69.2 to 77 | |
| Cr | 23 to 27 | |
| Mn | 0 to 1.5 | |
| Si | 0 to 1.0 | |
| Ni | 0 to 0.75 | |
| N | 0 to 0.25 | |
| C | 0 to 0.2 | |
| 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 A176: Standard Specification for Stainless and Heat-Resisting Chromium Steel Plate, Sheet, and Strip
EN 10095: Heat resisting steels and nickel alloys
ASTM A473: Standard Specification for Stainless Steel Forgings
ASTM A276: Standard Specification for Stainless Steel Bars and Shapes
Creep-Resistant Steels, Fujio Abe et al. (editors), 2008
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