ASTM A387 Grade 21 Class 2 Steel
Alloy Steels
Property Overview
Density7.9g/cm³
Elastic Modulus190GPa
Tensile Strength590MPa
Yield Strength350MPa
Brinell Hardness180HB
Maximum Service Temperature480°C
Chemical Composition
C
0.050 to 0.15%
CR
2.8 to 3.3%
MO
0.9 to 1.1%
MN
0.3 to 0.6%
SI
0 to 0.5%
P
0 to 0.025%
S
0 to 0.025%
FE
94.4 to 96%
Mechanical
Elastic (Young's, Tensile) Modulus
190 GPa
Elongation at Break
21 %
Fatigue Strength
250 MPa
Poisson's Ratio
0.29
Reduction in Area
34 %
Shear Modulus
74 GPa
Shear Strength
370 MPa
Tensile Strength: Ultimate (UTS)
590 MPa
Tensile Strength: Yield (Proof)
350 MPa
Hardness
Brinell Hardness
180
Physical
Density
7.9 g/cm 3
Thermal
Latent Heat of Fusion
260 J/g
Maximum Temperature: Mechanical
480 °C
Melting Completion (Liquidus)
1470 °C
Melting Onset (Solidus)
1430 °C
Specific Heat Capacity
470 J/kg-K
Thermal Conductivity
41 W/m-K
Thermal Diffusivity
11 mm 2 /s
Thermal Expansion
13 µm/m-K
Thermal Shock Resistance
17 points
Electrical
Electrical Conductivity: Equal Volume
7.6 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.8 % IACS
Calculated
PREN (Pitting Resistance)
6.4
Resilience: Ultimate (Unit Rupture Work)
110 MJ/m 3
Resilience: Unit (Modulus of Resilience)
320 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
4.1 % relative
Embodied Carbon
1.8 kg CO 2 /kg material
Embodied Energy
23 MJ/kg
Embodied Energy
23 MJ/kg 10 x 10 3 BTU/lb
Embodied Water
62 L/kg
Embodied Water
62 L/kg 7.4 gal/lb
Registered Designations & Aliases
ASTM A387 Grade 21 Class 2 Steel
Standards
ASTM A182 ASTM A182: Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service
ASTM A387 ASTM A387: Standard Specification for Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum
ASTM A387 ASTM A387: Standard Specification for Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum ASTM A182: Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011