AISI 439 (S43035) Stainless Steel
AISI 439 stainless steel is a ferritic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. 439 is the AISI designation for this material. S43035 is the UNS number.
The graph bars on the material properties cards below compare AISI 439 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
23 %
Fatigue Strength
170 MPa 25 x 103 psi
Poisson's Ratio
0.28
Reduction in Area
51 %
Rockwell B Hardness
78
Shear Modulus
77 GPa 11 x 106 psi
Shear Strength
310 MPa 45 x 103 psi
Tensile Strength: Ultimate (UTS)
490 MPa 70 x 103 psi
Tensile Strength: Yield (Proof)
250 MPa 36 x 103 psi
Thermal Properties
Latent Heat of Fusion
280 J/g
Maximum Temperature: Corrosion
530 °C 990 °F
Maximum Temperature: Mechanical
890 °C 1640 °F
Melting Completion (Liquidus)
1510 °C 2750 °F
Melting Onset (Solidus)
1430 °C 2600 °F
Specific Heat Capacity
480 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
25 W/m-K 14 BTU/h-ft-°F
Thermal Expansion
11 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.9 % IACS
Electrical Conductivity: Equal Weight (Specific)
3.4 % IACS
Otherwise Unclassified Properties
Base Metal Price
9.0 % relative
Calomel Potential
-220 mV
Density
7.7 g/cm3 480 lb/ft3
Embodied Carbon
2.3 kg CO2/kg material
Embodied Energy
34 MJ/kg 14 x 103 BTU/lb
Embodied Water
120 L/kg 15 gal/lb
Common Calculations
PREN (Pitting Resistance)
18
Resilience: Ultimate (Unit Rupture Work)
95 MJ/m3
Resilience: Unit (Modulus of Resilience)
160 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
18 points
Strength to Weight: Bending
18 points
Thermal Diffusivity
6.7 mm2/s
Thermal Shock Resistance
16 points
Alloy Composition
Among wrought stainless steels, the composition of AISI 439 stainless steel is notable for including aluminum (Al) and titanium (Ti). Aluminum is used to improve oxidation resistance. It can also enhance the effects of heat treatment. Titanium is used to broadly improve mechanical properties.
| Fe | 77.1 to 82.8 | |
| Cr | 17 to 19 | |
| Ti | 0.2 to 1.1 | |
| Mn | 0 to 1.0 | |
| Si | 0 to 1.0 | |
| Ni | 0 to 0.5 | |
| Al | 0 to 0.15 | |
| 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 A479: Standard Specification for Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels
ASTM A276: Standard Specification for Stainless Steel Bars and Shapes
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
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
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