Chemical composition:
Carbon C: 0.27 ~ 0.35
Si Si: 0.15 ~ 0.35
Manganese Mn: 0.35 ~ 0.65
Sulfur S: to allow the residual content ≤ 0.030
Phosphorus P: ≤ 0.030 to allow the residual content of chromium Cr: 0.60 ~ 1.00
Ni-Ni: 2.50 ~ 3.00
Copper Cu: to allow the residual content of ≤ 0.030 [1]
Mechanical properties:
Tensile strength σb (MPa): ≥ 980 (100)
Yield strength σs (MPa): ≥ 785 (80)
Elongation δ5 (%): ≥ 9
Reduction of area ψ (%): ≥ 45
Impact energy Akv (J): ≥ 63
Impact toughness αkv (J/cm2): ≥ 78 (8)
Hardness: ≤ 241HB
Sample size: Sample size of rough 25mm [2]
Heat treatment and microstructure specifications:
Standard heat treatment: quenching 820 ℃, oil cooling; tempering 500 ℃, water-cooled, oil-cooling.
● Delivery status: to heat treatment (normalizing, annealing, or tempering) or heat treatment delivery, delivery status should be indicated in the contract