Bearing Steel

● chemical composition:c: 0.17 ~ 0.23 (tolerance: ± 0.02), si: 0.15 ~ 0.35 (tolerance: ± 0.03)mn: 0.60 ~ 0.95 (tolerance: ± 0.04), s: ≤ 0.015 (tolerance: 0.005)p: ≤ 0.025 (tolerance: 0.005), cr: 0.35 ~ 0.65 (tolerance: ± 0.15)ni: 0.35 ~ 0.75 (tolerance: ± 0.05), cu: ≤ 0.30 (tolerance: +0.05)mo: 0.15 ~ 0.25 (tolerance: ± 0.02)
● mechanical properties:tensile strength σb (mpa): ≥ 1176 (120)elongation δ5 (%): ≥ 9reduction of area ψ (%): ≥ 45impact toughness αkv (j/cm2): ≥ 78 (8)sample size: sample size is 15mmheat treatment specifications: quenching, the first 880 ± 20 ℃, the second time 790 ± 20 ℃, oil cooling; tempering, 150 ~ 200 ℃, air cooling.microstructure: martensite.