UNS S44700 (29-4) Stainless Steel
S44700 stainless steel is a ferritic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. S44700 is the UNS number for this material. 29-4 is the common industry name.
It has a fairly high base cost among wrought ferritic stainless steels. In addition, it has a fairly high embodied energy and a moderately high tensile strength.
The graph bars on the material properties cards below compare S44700 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
200
Elastic (Young's, Tensile) Modulus
210 GPa 30 x 106 psi
Elongation at Break
23 %
Fatigue Strength
300 MPa 43 x 103 psi
Poisson's Ratio
0.27
Reduction in Area
45 %
Rockwell C Hardness
17
Shear Modulus
82 GPa 12 x 106 psi
Shear Strength
380 MPa 55 x 103 psi
Tensile Strength: Ultimate (UTS)
600 MPa 86 x 103 psi
Tensile Strength: Yield (Proof)
450 MPa 65 x 103 psi
Thermal Properties
Latent Heat of Fusion
300 J/g
Maximum Temperature: Corrosion
460 °C 870 °F
Maximum Temperature: Mechanical
1100 °C 2010 °F
Melting Completion (Liquidus)
1460 °C 2660 °F
Melting Onset (Solidus)
1410 °C 2580 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Expansion
11 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
18 % relative
Density
7.8 g/cm3 480 lb/ft3
Embodied Carbon
3.6 kg CO2/kg material
Embodied Energy
49 MJ/kg 21 x 103 BTU/lb
Embodied Water
180 L/kg 22 gal/lb
Common Calculations
PREN (Pitting Resistance)
42
Resilience: Ultimate (Unit Rupture Work)
120 MJ/m3
Resilience: Unit (Modulus of Resilience)
480 kJ/m3
Stiffness to Weight: Axial
15 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
21 points
Strength to Weight: Bending
20 points
Thermal Shock Resistance
19 points
Alloy Composition
Among wrought stainless steels, the composition of S44700 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 | 64.9 to 68.5 | |
| Cr | 28 to 30 | |
| Mo | 3.5 to 4.2 | |
| Mn | 0 to 0.3 | |
| Si | 0 to 0.2 | |
| Ni | 0 to 0.15 | |
| Cu | 0 to 0.15 | |
| P | 0 to 0.025 | |
| S | 0 to 0.020 | |
| N | 0 to 0.020 | |
| C | 0 to 0.010 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A493: Standard Specification for Stainless Steel Wire and Wire Rods for Cold Heading and Cold Forging
ASTM A479: Standard Specification for Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels
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
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
Properties and Selection: Irons, Steels and High Performance Alloys, ASM Handbook vol. 1, ASM International, 1993
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