SAE-AISI 4340M (300M, K44220) Silicon-Vanadium Steel
Alloy Steels
Property Overview
Density7.8g/cm³
Elastic Modulus190GPa
Tensile Strength2340MPa
Yield Strength1240MPa
Brinell Hardness710HB
Maximum Service Temperature430°C
Chemical Composition
C
0.38 to 0.43%
CR
0.7 to 1.0%
NI
1.7 to 2.0%
MO
0.35 to 0.45%
MN
0.65 to 0.9%
SI
1.5 to 1.8%
P
0 to 0.012%
S
0 to 0.012%
V
0.050 to 0.1%
FE
93.3 to 94.8%
Mechanical
Elastic (Young's, Tensile) Modulus
190 GPa
Elongation at Break
6.0 %
Fatigue Strength
690 MPa
Fracture Toughness
60 MPa-m 1/2
Impact Strength: V-Notched Charpy
18 J
Poisson's Ratio
0.29
Shear Modulus
72 GPa
Shear Strength
1360 MPa
Tensile Strength: Ultimate (UTS)
2340 MPa
Tensile Strength: Yield (Proof)
1240 MPa
Hardness
Brinell Hardness
710
Rockwell C Hardness
55
Physical
Density
7.8 g/cm 3
Thermal
Latent Heat of Fusion
280 J/g
Maximum Temperature: Mechanical
430 °C
Melting Completion (Liquidus)
1440 °C
Melting Onset (Solidus)
1400 °C
Specific Heat Capacity
480 J/kg-K
Thermal Conductivity
38 W/m-K
Thermal Diffusivity
10 mm 2 /s
Thermal Expansion
13 µm/m-K
Thermal Shock Resistance
70 points
Electrical
Electrical Conductivity: Equal Volume
7.8 % IACS
Electrical Conductivity: Equal Weight (Specific)
9.1 % IACS
Calculated
PREN (Pitting Resistance)
2.2
Resilience: Ultimate (Unit Rupture Work)
120 MJ/m 3
Resilience: Unit (Modulus of Resilience)
4120 kJ/m 3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
84 points
Strength to Weight: Bending
51 points
Environmental
Base Metal Price
3.9 % relative
Embodied Carbon
1.9 kg CO 2 /kg material
Embodied Energy
26 MJ/kg
Embodied Energy
26 MJ/kg 11 x 10 3 BTU/lb
Embodied Water
55 L/kg
Embodied Water
55 L/kg 6.5 gal/lb
Registered Designations & Aliases
300MK44220SAE-AISI 4340M (300M, K44220) Silicon-Vanadium Steel
Standards
ASTM A646 ASTM A646: Standard Specification for Premium Quality Alloy Steel Blooms and Billets for Aircraft and Aerospace Forgings