MakeItFrom.com
Menu (ESC)

ACI-ASTM CF8 Steel vs. R31539 Cobalt

ACI-ASTM CF8 steel belongs to the iron alloys classification, while R31539 cobalt belongs to the cobalt alloys. They have a modest 22% of their average alloy composition in common, which, by itself, doesn't mean much. There are 27 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown.

For each property being compared, the top bar is ACI-ASTM CF8 steel and the bottom bar is R31539 cobalt.

Metric UnitsUS Customary Units

Mechanical Properties

Elastic (Young's, Tensile) Modulus, GPa 200
220
Elongation at Break, % 55
13 to 22
Fatigue Strength, MPa 260
310 to 480
Poisson's Ratio 0.28
0.29
Shear Modulus, GPa 77
86
Tensile Strength: Ultimate (UTS), MPa 540
1000 to 1340
Tensile Strength: Yield (Proof), MPa 260
590 to 940

Thermal Properties

Latent Heat of Fusion, J/g 300
320
Melting Completion (Liquidus), °C 1420
1360
Melting Onset (Solidus), °C 1430
1290
Specific Heat Capacity, J/kg-K 480
450
Thermal Conductivity, W/m-K 16
13
Thermal Expansion, µm/m-K 15
13

Electrical Properties

Electrical Conductivity: Equal Volume, % IACS 2.0
2.0
Electrical Conductivity: Equal Weight (Specific), % IACS 2.3
2.1

Otherwise Unclassified Properties

Density, g/cm3 7.8
8.4
Embodied Carbon, kg CO2/kg material 3.1
8.2
Embodied Energy, MJ/kg 44
110
Embodied Water, L/kg 150
530

Common Calculations

Resilience: Ultimate (Unit Rupture Work), MJ/m3 240
140 to 190
Resilience: Unit (Modulus of Resilience), kJ/m3 160
780 to 2000
Stiffness to Weight: Axial, points 14
15
Stiffness to Weight: Bending, points 25
24
Strength to Weight: Axial, points 19
33 to 44
Strength to Weight: Bending, points 19
27 to 32
Thermal Diffusivity, mm2/s 4.3
3.5
Thermal Shock Resistance, points 13
24 to 32

Alloy Composition

Aluminum (Al), % 0
0.3 to 1.0
Carbon (C), % 0 to 0.080
0 to 0.14
Chromium (Cr), % 18 to 21
26 to 30
Cobalt (Co), % 0
57.7 to 68.7
Iron (Fe), % 63.8 to 74
0 to 0.75
Lanthanum (La), % 0
0.030 to 0.2
Manganese (Mn), % 0 to 1.5
0 to 1.0
Molybdenum (Mo), % 0 to 0.5
5.0 to 7.0
Nickel (Ni), % 8.0 to 11
0 to 1.0
Nitrogen (N), % 0
0 to 0.25
Phosphorus (P), % 0 to 0.040
0
Silicon (Si), % 0 to 2.0
0 to 1.0
Sulfur (S), % 0 to 0.040
0