Annealed 4320 Ni-Cr-Mo Steel
Annealed SAE-AISI 4320 is SAE-AISI 4320 steel in the annealed condition. The graph bars on the material properties cards below compare annealed SAE-AISI 4320 to: SAE-AISI wrought 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
190 GPa 27 x 106 psi
Elongation at Break
29 %
Fatigue Strength
320 MPa 47 x 103 psi
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
370 MPa 54 x 103 psi
Tensile Strength: Ultimate (UTS)
570 MPa 83 x 103 psi
Tensile Strength: Yield (Proof)
430 MPa 62 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
420 °C 790 °F
Melting Completion (Liquidus)
1460 °C 2660 °F
Melting Onset (Solidus)
1420 °C 2590 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
46 W/m-K 27 BTU/h-ft-°F
Thermal Expansion
11 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.4 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.5 % IACS
Otherwise Unclassified Properties
Base Metal Price
3.4 % relative
Density
7.9 g/cm3 490 lb/ft3
Embodied Carbon
1.7 kg CO2/kg material
Embodied Energy
22 MJ/kg 9.4 x 103 BTU/lb
Embodied Water
52 L/kg 6.2 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
150 MJ/m3
Resilience: Unit (Modulus of Resilience)
480 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
20 points
Strength to Weight: Bending
19 points
Thermal Diffusivity
13 mm2/s
Thermal Shock Resistance
19 points
Alloy Composition
| Fe | 95.8 to 97 | |
| Ni | 1.7 to 2.0 | |
| Mn | 0.45 to 0.65 | |
| Cr | 0.4 to 0.6 | |
| Si | 0.15 to 0.35 | |
| Mo | 0.2 to 0.3 | |
| C | 0.17 to 0.22 | |
| S | 0 to 0.040 | |
| P | 0 to 0.035 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
ASTM A752: Standard Specification for General Requirements for Wire Rods and Coarse Round Wire, Alloy Steel
ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996
Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015