Material Name: 85 spring steel
Standard: GB / T 1222-1984
● Features and application:
Similar performance with 65,70 gauge steel, high strength, mainly used for smaller size of the spring, such as cars, tractors and other machinery or train to withstand vibration of flat circular spring and coil spring.
● Chemical Composition:
Carbon C: 0.82 ~ 0.90 Si Si: 0.17 ~ 0.37
Manganese Mn: 0.50 ~ 0.80
Sulfur S: ≤ 0.035
Phosphorus P: ≤ 0.035
Chromium Cr: ≤ 0.25
Ni-Ni: ≤ 0.25
Copper Cu: ≤ 0.25
● Mechanical Properties:
Tensile strength σb (MPa): ≥ 1127 (115)
Yield strength σs (MPa): ≥ 980 (100)
Elongation δ10 (%): ≥ 6
Reduction of area ψ (%): ≥ 30
Hardness: hot, ≤ 302HB; cold-drawn + heat treatment, ≤ 321HB
● Heat treatment and microstructure specifications:
Standard heat treatment: quenching 820 ℃ ± 20 ℃, oil cooling; tempering 480 ℃ ± 50 ℃ (special needs, ± 30 ℃).
● Delivery status: hot-rolled steel to heat treatment or heat treatment delivery, cold-drawn steel with heat treatment delivery.
