60CrMnBA spring steel
Features and Scope
60CrMnBA spring steel high strength, ductility and toughness, good hardenability, heat-sensitive than the low-manganese steel, higher than the Si-Mn steel, silico-manganese steel decarburization tendency than the small, temper brittleness. It should select the appropriate tempering temperature and cooling rate; general state quenching and tempering temperature used 60CrMnBA for vehicles, tractors industrial production of heavy load, stress and a larger spring diameter larger coil spring.
Chemical composition:
Carbon C: 0.56 ~ 0.64
Si Si: 0.17 ~ 0.37
Manganese Mn: 0.70 ~ 1.00
Chromium Cr: 0.70 ~ 1.00
Sulfur S: ≤ 0.025
Phosphorus P: ≤ 0.025
Ni-Ni: ≤ 0.35
Copper Cu: ≤ 0.25
Boron B: 0.0005 ~ 0.0040
Mechanical properties
Tensile strength σb (MPa): ≥ 1225 (125)
Conditions yield strength σ0.2 (MPa): ≥ 1080 (Rp0.2)
Elongation δ5 (%): ≥ 9 (for reference)
Reduction of area ψ (%): ≥ 20
Hardness: hot, ≤ 321HB; cold-drawn + heat treatment, ≤ 321HB
Standard heat treatment and microstructure
Standard heat treatment: quenching 830 ~ 860 ℃, oil cooling; tempering 460 ~ 520 ℃.
Delivery status: hot-rolled steel to heat treatment or heat treatment delivery, cold-drawn steel with heat treatment delivery.
