(Cementite) bearing steel: 20NiCrMo2

● Features and application:
Is a commonly used alloy carburizing steel, carburizing treatment has a high surface hardness, wear resistance and contact fatigue strength, while the Department has retained a good heart toughness that can withstand high impact loads. Mainly used for automotive bearings and other impact-resistant, wear-resistant parts of the material.
● Chemical Composition:
Carbon C: 0.17 ~ 0.23 (tolerance: ± 0.02)
Si Si: 0.15 ~ 0.40 (tolerance: ± 0.03)
Manganese Mn: 0.60 ~ 0.90 (tolerance: ± 0.04)
Sulfur S: ≤ 0.030 (tolerance: 0.005)
Phosphorus P: ≤ 0.030 (tolerance: 0.005)
Chromium Cr: 0.35 ~ 0.65 (tolerance: ± 0.15)
Ni-Ni: 0.40 ~ 0.70 (tolerance: ± 0.05)
Copper Cu: ≤ 0.25 (Tolerance: +0.05)
Mo Mo: 0.15 ~ 0.30 (tolerance: ± 0.02)
● Mechanical Properties:
Tensile strength σb (MPa): ≥ 1176 (120)
Elongation δ5 (%): ≥ 9
Reduction of area ψ (%): ≥ 45
Impact toughness αkv (J/cm2): ≥ 78 (8)
Sample Size: Sample size is 15mm
● Heat treatment and microstructure specifications:
Standard heat treatment: quenching, the first 880 ± 20 ℃, the second 790 ± 20 ℃, oil cooling; tempering, 150 ~ 200 ℃, air-cooled.
Microstructure: martensite.
● Delivery status: hot-rolled or forged steel with hot-rolled (forged) state or annealed state delivery. Cold-drawn steel in the annealed condition delivered.