20CrNiMoA directory
Cross-reference
China: GB / T 3077-1999 (20CrNiMoA)
20CrNiMoA International Organization for Standardization: ISO 683-11 1987 E (20NiCrMo2 20NiCrMoS2)
United States: ASTM A29-1993a (8615 8617 8620 8622)
Japan: JIS G4103-1979 (SNCM220)
Material Name: alloy steel grades: 20CrNiMoA Standard: GB / T 3077-1999
Chemical composition
Carbon C: 0.17 ~ 0.23
Si Si: 0.17 ~ 0.37
Manganese Mn: 0.60 ~ 0.95
Sulfur S: to allow the residual content of ≤ 0.035
Phosphorus P: allow the residual content ≤ 0.035
Chromium Cr: 0.40 ~ 0.70
Ni-Ni: 0.35 ~ 0.75
Copper Cu: to allow the residual content ≤ 0.030
Mo Mo: 0.20 ~ 0.30
Mechanical properties
Tensile strength σb (MPa): ≥ 980 (100)
Yield strength σs (MPa): ≥ 785 (80)
Elongation δ5 (%): ≥ 9
Reduction of area ψ (%): ≥ 40
Impact energy Akv (J): ≥ 47
Impact toughness αkv (J/cm2): ≥ 59 (6)
Hardness: ≤ 197HB
Sample size: Sample size is 15mm rough
Heat treatment
Standard heat treatment: quenching 850 ℃, oil cooling; tempering 200 ℃, air-cooled. Delivery status: to heat treatment (normalizing, annealing, or tempering) or heat treatment delivery, delivery status should be indicated in the contract.
