3/4-Hard 302 Stainless Steel
3/4-hard AISI 302 is AISI 302 stainless steel in the 3/4-hard temper. It has the second highest strength and second lowest ductility compared to the other variants of AISI 302 stainless steel. The graph bars on the material properties cards below compare 3/4-hard AISI 302 to: wrought austenitic 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
420
Elastic (Young's, Tensile) Modulus
200 GPa 29 x 106 psi
Elongation at Break
6.8 %
Fatigue Strength
520 MPa 75 x 103 psi
Poisson's Ratio
0.28
Shear Modulus
77 GPa 11 x 106 psi
Shear Strength
800 MPa 120 x 103 psi
Tensile Strength: Ultimate (UTS)
1370 MPa 200 x 103 psi
Tensile Strength: Yield (Proof)
1040 MPa 150 x 103 psi
Thermal Properties
Latent Heat of Fusion
280 J/g
Maximum Temperature: Corrosion
410 °C 780 °F
Maximum Temperature: Mechanical
710 °C 1300 °F
Melting Completion (Liquidus)
1420 °C 2590 °F
Melting Onset (Solidus)
1400 °C 2550 °F
Specific Heat Capacity
480 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
16 W/m-K 9.4 BTU/h-ft-°F
Thermal Expansion
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
2.4 % IACS
Electrical Conductivity: Equal Weight (Specific)
2.8 % IACS
Otherwise Unclassified Properties
Base Metal Price
15 % relative
Calomel Potential
-70 mV
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
3.0 kg CO2/kg material
Embodied Energy
42 MJ/kg 18 x 103 BTU/lb
Embodied Water
140 L/kg 17 gal/lb
Common Calculations
PREN (Pitting Resistance)
19
Resilience: Ultimate (Unit Rupture Work)
86 MJ/m3
Resilience: Unit (Modulus of Resilience)
2750 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
49 points
Strength to Weight: Bending
35 points
Thermal Diffusivity
4.4 mm2/s
Thermal Shock Resistance
29 points
Alloy Composition
| Fe | 67.9 to 75 | |
| Cr | 17 to 19 | |
| Ni | 8.0 to 10 | |
| Mn | 0 to 2.0 | |
| Si | 0 to 0.75 | |
| C | 0 to 0.15 | |
| N | 0 to 0.1 | |
| P | 0 to 0.045 | |
| S | 0 to 0.030 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
ASTM A666: Standard Specification for Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate, and Flat Bar
ASTM A276: Standard Specification for Stainless Steel Bars and Shapes
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 Austenitic Stainless Steels: Mechanism, Mitigation and Monitoring, H. S. Khatak and B. Raj (editors), 2002
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
Austenitic Stainless Steels: Microstructure and Mechanical Properties, P. Marshall, 1984
Properties and Selection: Irons, Steels and High Performance Alloys, ASM Handbook vol. 1, ASM International, 1993
ASM Specialty Handbook: Stainless Steels, J. R. Davis (editor), 1994
Advances in Stainless Steels, Baldev Raj et al. (editors), 2010