EN 1.7027 (20Cr4) Case-Hardening Bearing Steel
Alloy Steels
annealed
Property Overview
Density7.8g/cm³
Elastic Modulus190GPa
Tensile Strength600MPa
Yield Strength390MPa
Brinell Hardness180HB
Maximum Service Temperature420°C
Chemical Composition
C
0.17 to 0.23%
CR
0.9 to 1.2%
MN
0.6 to 0.9%
SI
0 to 0.4%
P
0 to 0.025%
S
0 to 0.030%
CU
0 to 0.3%
AL
0 to 0.050%
O
0 to 0.0020%
FE
97.1 to 98.5%
Mechanical
Elastic (Young's, Tensile) Modulus
190 GPa
Elongation at Break
22 %
Fatigue Strength
280 MPa
Poisson's Ratio
0.29
Shear Modulus
73 GPa
Shear Strength
380 MPa
Tensile Strength: Ultimate (UTS)
600 MPa
Tensile Strength: Yield (Proof)
390 MPa
Hardness
Brinell Hardness
180
Physical
Density
7.8 g/cm 3
Thermal
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
420 °C
Melting Completion (Liquidus)
1460 °C
Melting Onset (Solidus)
1420 °C
Specific Heat Capacity
470 J/kg-K
Thermal Conductivity
45 W/m-K
Thermal Diffusivity
12 mm 2 /s
Thermal Expansion
13 µm/m-K
Thermal Shock Resistance
18 points
Electrical
Electrical Conductivity: Equal Volume
7.2 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.3 % IACS
Calculated
Resilience: Ultimate (Unit Rupture Work)
120 MJ/m 3
Resilience: Unit (Modulus of Resilience)
410 kJ/m 3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
21 points
Strength to Weight: Bending
20 points
Environmental
Base Metal Price
2.3 % relative
Embodied Carbon
1.4 kg CO 2 /kg material
Embodied Energy
19 MJ/kg
Embodied Energy
19 MJ/kg 8.2 x 10 3 BTU/lb
Embodied Water
51 L/kg
Embodied Water
51 L/kg 6.1 gal/lb
Registered Designations & Aliases
1.702720Cr4EN 1.7027 (20Cr4) Case-Hardening Bearing Steel
Standards
ISO 683-17 ISO 683-17: Heat-treated steels, alloy steels and free-cutting steels - Part 17: Ball and roller bearing steels
ISO 683-17 ISO 683-17: Heat-treated steels, alloy steels and free-cutting steels - Part 17: Ball and roller bearing steels Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005