Material Name: 55SiMnVB spring steel

Standard: GB / T 1222-1984
● Features and Scope:
Low content of alloying elements, high hardenability than 60Si2Mn, higher ductility and toughness, small decarbonization tendencies, good temper resistance, good thermal processing performance and low cost. Instead 60Si2MnA production of heavy, medium and small automobile leaf springs and other medium-sized section of the leaf spring and coil spring.
● Chemical Composition:
Carbon C: 0.52 ~ 0.60
Si Si: 0.70 ~ 1.00
Mn Mn: 1.00 ~ 1.30
Sulfur S: ≤0.035
Phosphorus P: ≤0.035
Chromium Cr: ≤0.35
Ni Ni: ≤0.35
Copper Cu: ≤0.25
Vanadium V: 0.08 ~ 0.16
Boron B: 0.0005 ~ 0.0035
● Mechanical Properties:
Tensile strength σb (MPa): ≥1372 (140)
Yield strength σs (MPa): ≥1225 (125)
Elongation δ10 (%): ≥5
Reduction of ψ (%): ≥30
Hardness: hot, ≤321HB; Cold Drawn + heat, ≤321HB
● Heat treatment and microstructure specifications:
Heat treatment specifications: quenching 860 ℃ ± 20 ℃, oil cooling; tempering 460 ℃ ± 50 ℃ (when special needs, ± 30 ℃).
Microstructure: sorbite.
● Delivery status: hot-rolled steel to heat treatment or heat treatment delivery, cold drawn steel to heat treatment delivery.