Chemical composition
Carbon C: 0.95 ~ 1.05
Si Si: 0.15 ~ 0.35
Manganese Mn: 0.25 ~ 0.45
Sulfur S: ≤ 0.025
Phosphorus P: ≤ 0.025
Chromium Cr: 1.40 ~ 1.65
Ni: to allow the residual content of ≤ 0.30
Copper Cu: to allow the residual content of ≤ 0.25
Mo Mo: allow the residual content of ≤ 0.08
Note: The allows the residual content of Ni + Cu ≤ 0.50 [1]
Mechanical properties
Tensile strength σb (MPa): 1617
Impact energy Akv (J): 28
Hardness: 61 ~ 64HRC
Sample size: a sample
Standard heat treatment and microstructure
Heat treatment specifications: 850 ~ 860 ℃ quenching oil cooling; 160 ℃ tempering 2h.
Microstructure: martensite.
● Delivery status: the hot-rolled (forged) annealing, not annealed, annealed steel strip, cold-drawn (rolled) round, polished round steel, hot-rolled steel, annealed steel strip, cold-drawn (rolled) steel eight kinds of state of delivery.