Carbon C: 0.18 ~ 0.23 8620h 
 Silicon Si: 0.15 ~ 0.35 Mn Mn: 0.70 ~ 0.90 Sulfur S: allow the residual content of ≤ 0.035 phosphorus P: allow the residual content of ≤ 0.035 Chromium Cr: 0.40 ~ 0.60 Nickel Ni: 0.40 ~ 0.70 Copper Cu: allow the residual content of ≤ 0.030 Mo Mo : 0.15 to 0.25 

 Mechanical properties 
 Tensile strength σb (MPa): ≥ 980 (100) yield strength σs (MPa): ≥ 785 (80) the elongation δ5 (%): ≥ 9 Reduction of area ψ (%): ≥ 40 impact energy Akv (J ): ≥ 47 impact toughness the value αkv (J/cm2): ≥ 59 (6) Hardness: ≤ 197HB