40CRmoV5 chemical composition%: C0.32 ~ 0.45 Si0.80 ~ 1.20 Mn0.20 ~ 0.50 Cr4.75 ~ 5.50 Mo1.10 ~ 1.75 V0.80 ~ 1.20 p less than or equal less than equal to 0.030 S 0.030; heat treatment: (cross-cargo status: Brinell hardness HBW10/3000 (less than equal to 235)) quenching: 790 degrees + -15 degrees warm, 1,000 degrees (salt) or 1010 degrees (oven controlled atmosphere) + -6 degree heat, heat 5 15min air-cooled, 550 degrees + -6 degrees tempering; annealing, thermal processing