R31538 Cobalt vs. Grade 361 Molybdenum

R31538 cobalt belongs to the cobalt alloys classification, while grade 361 molybdenum belongs to the otherwise unclassified metals. There are 20 material properties with values for both materials. Properties with values for just one material (9, in this case) are not shown.

For each property being compared, the top bar is R31538 cobalt and the bottom bar is grade 361 molybdenum.

High Carbon Co-28Cr-6Mo Alloy (ASTM F1537 Alloy 2, ISO 5832-12 Alloy 2, R31538)Grade 361 Molybdenum

Metric UnitsUS Customary Units

Mechanical Properties

Elastic (Young's, Tensile) Modulus, GPa		220
Elastic (Young's, Tensile) Modulus, GPa		310

Elongation at Break, %		13 to 23
Elongation at Break, %		6.3

Poisson's Ratio		0.29
Poisson's Ratio		0.31

Shear Modulus, GPa		86
Shear Modulus, GPa		120

Tensile Strength: Ultimate (UTS), MPa		1020 to 1360
Tensile Strength: Ultimate (UTS), MPa		620

Tensile Strength: Yield (Proof), MPa		580 to 930
Tensile Strength: Yield (Proof), MPa		530

Thermal Properties

Latent Heat of Fusion, J/g		320
Latent Heat of Fusion, J/g		370

Specific Heat Capacity, J/kg-K		450
Specific Heat Capacity, J/kg-K		250

Thermal Expansion, µm/m-K		13
Thermal Expansion, µm/m-K		7.0

Otherwise Unclassified Properties

Density, g/cm³		8.4
Density, g/cm³		10

Embodied Carbon, kg CO₂/kg material		8.1
Embodied Carbon, kg CO₂/kg material		28

Embodied Energy, MJ/kg		110
Embodied Energy, MJ/kg		330

Embodied Water, L/kg		530
Embodied Water, L/kg		360

Common Calculations

Resilience: Ultimate (Unit Rupture Work), MJ/m³		140 to 200
Resilience: Ultimate (Unit Rupture Work), MJ/m³		37

Resilience: Unit (Modulus of Resilience), kJ/m³		750 to 1920
Resilience: Unit (Modulus of Resilience), kJ/m³		450

Stiffness to Weight: Axial, points		15
Stiffness to Weight: Axial, points		17

Stiffness to Weight: Bending, points		24
Stiffness to Weight: Bending, points		22

Strength to Weight: Axial, points		34 to 45
Strength to Weight: Axial, points		17

Strength to Weight: Bending, points		27 to 32
Strength to Weight: Bending, points		16

Thermal Shock Resistance, points		25 to 33
Thermal Shock Resistance, points		21

Alloy Composition

Carbon (C), %		0.15 to 0.35
Carbon (C), %		0 to 0.010

Chromium (Cr), %		26 to 30
Chromium (Cr), %		0

Cobalt (Co), %		58.7 to 68.9
Cobalt (Co), %		0

Iron (Fe), %		0 to 0.75
Iron (Fe), %		0 to 0.010

Manganese (Mn), %		0 to 1.0
Manganese (Mn), %		0

Molybdenum (Mo), %		5.0 to 7.0
Molybdenum (Mo), %		99.9 to 100

Nickel (Ni), %		0 to 1.0
Nickel (Ni), %		0 to 0.0050

Nitrogen (N), %		0 to 0.25
Nitrogen (N), %		0 to 0.0020

Oxygen (O), %		0
Oxygen (O), %		0 to 0.0070

Silicon (Si), %		0 to 1.0
Silicon (Si), %		0 to 0.010