Material Name: Gear Steel 20CrMo

● Features and Scope:
High hardenability, no temper brittleness, very good weldability, cold cracking tendency to form small, can be a good machinability and cold strain plasticity. Usually in the quenched and tempered or carburizing state used for the manufacture of infiltration in non-corrosive media and the operating temperature is below 250 ℃, pressure pipe and various fasteners containing nitrogen and hydrogen mixture of media work, more advanced carbon parts, such as gears, shafts, etc.
● Chemical Composition:
Carbon C: 0.17 ~ 0.24
Si Si: 0.17 ~ 0.37
Mn Mn: 0.40 ~ 0.70
Sulfur S: to allow the residual content ≤0.035
Phosphorus P: to allow the residual content ≤0.035
Chromium Cr: 0.80 ~ 1.10
Ni: to allow the residual content ≤0.030
Cu: to allow the residual content ≤0.030
Mo Mo: 0.15 ~ 0.25
● Mechanical Properties:
Tensile strength σb (MPa): ≥885 (90)
Yield strength σs (MPa): ≥685 (70)
Elongation δ5 (%): ≥12
Reduction of ψ (%): ≥50
Impact energy Akv (J): ≥78
Impact toughness αkv (J / cm2): ≥98 (10)
Hardness: ≤197HB
Sample size: Sample size is 15mm rough
● Heat treatment and microstructure specifications:
Heat treatment specifications: quenching 880 ℃, water, oil cooling; tempering 500 ℃, water, oil cooling.
● Delivery status: to heat treatment (normalizing, annealing or tempering) or without heat treatment delivery, the delivery status should be specified in the contract.