Description: Gear Steel: 40CrNiMo Standard: GB / T 3077-1988 ● Chemical Composition: Carbon C: 0.37 ~ 0.44 Si Si: 0.17 ~ 0.37 Mn Mn: 0.50 ~ 0.80 Sulfur S: allow the residual content ≤0.025 Phosphorus P: to allow the residual content ≤0.025 Chromium Cr: 0.60 ~ 0.90 Ni Ni: 1.25 ~ 1.65 Cu: to allow the residual content ≤0.025 Mo Mo: 0.15 ~ 0.25 ● Mechanical Properties: Tensile strength σb (MPa): ≥980 (100) Yield strength σs (MPa): ≥835 (85) Elongation δ5 (%): ≥12 Reduction of area ψ (%): ≥55 Impact energy Akv (J): ≥78 Impact toughness αkv (J / cm2): ≥98 (10) Hardness: ≤269HB Sample size: Sample size is 25mm rough ● Heat treatment and microstructure specifications: Heat treatment specifications: quenching 850 ℃, oil cooling; tempering 600 ℃, 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. |