Material Name: Gear Steel 42CrMo

Standard: GB / T 3077-1988
● Features and Scope:
Strength, hardenability, good toughness, when small deformation hardening, high strength and creep rupture strength at high temperatures. Requirements for the manufacture of higher intensity than the 35CrMo steel and tempered forgings larger cross-section, such as the big locomotive traction gears, supercharger drive gear, rear axle, greatly affected by the load rod and spring, can also be used 2000m or less deep oil drill pipe joints and salvage tools.
● Chemical Composition:
Carbon C: 0.38 ~ 0.45
Si Si: 0.17 ~ 0.37
Mn Mn: 0.50 ~ 0.80
Sulfur S: to allow the residual content ≤0.035
Phosphorus P: to allow the residual content ≤0.035
Chromium Cr: 0.90 ~ 1.20
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): ≥1080 (110)
Yield strength σs (MPa): ≥930 (95)
Elongation δ5 (%): ≥12
Reduction of ψ (%): ≥45
Impact energy Akv (J): ≥63
Impact toughness αkv (J / cm2): ≥78 (8)
Hardness: ≤217HB
Sample size: Sample size is 25mm rough
● Heat treatment and microstructure specifications:
Heat treatment specifications: quenching 850 ℃, oil cooling; tempering 560 ℃, water, oil cooling.
Microstructure: sorbite.
● Delivery status: to heat treatment (normalizing, annealing or tempering) or without heat treatment delivery, the delivery status should be specified in the contract.