Material Name: Alloy Steel
Grade: 20Cr2Ni4A
● Features and application:
Is a high-quality alloy steel, high strength, good toughness and hardenability. Can not be directly after carburizing quenching, in order to reduce the surface retained austenite. Machinability and cold plastic deformation general. Poor welding, preheating before welding to be about 150 ℃, hours white point sensitivity, a tendency to temper brittleness. Carburizing conditions for large sections, such as large gears, shafts and require high strength, toughness, good conditioning parts.
● Chemical Composition:
Carbon C: 0.17 ~ 0.23
Si Si: 0.17 ~ 0.37
Manganese Mn: 0.30 ~ 0.60
Sulfur S: ≤ 0.03
Phosphorus P: ≤ 0.03
Chromium Cr: 1.25 ~ 1.65
Ni-Ni: 3.25 ~ 3.65
● Mechanical Properties:
Tensile strength σb (MPa): 1483
Conditions yield strength σ0.2 (MPa): 1292
Elongation δ5 (%): 13
Reduction of area ψ (%): 57
Impact toughness αkv (J/cm2): 75
Hardness: 434HB
Sample size: a test material
● Heat treatment and microstructure specifications:
Heat treatment specifications: 880 ℃ +780 ℃ oil quenching oil quenched, 200 ℃ tempering.