Material Name: SUP7
● Features and Scope:
Is widely used silicon manganese spring steel, strength, flexibility and hardenability than 55Si2Mn. Suitable for railway vehicles, bear a greater load on the automobile and tractor industries flat spring or coil spring 30mm or less in diameter, and is also suitable for the production of working temperature below 250 ℃ non-corrosive medium heat and withstand alternating load spring and under high stress the important work of the large spring roll.
● Chemical Composition:
Carbon C: 0.56 ~ 0.64
Si Si: 1.50 ~ 2.00
Mn Mn: 0.60 ~ 0.90
Sulfur S: ≤0.035
Phosphorus P: ≤0.035
Chromium Cr: ≤0.35
Ni Ni: ≤0.35
Copper Cu: ≤0.25
● Mechanical Properties:
Tensile strength σb (MPa): ≥1274 (130)
Yield strength σs (MPa): ≥1176 (120)
Elongation δ10 (%): ≥5
Reduction of ψ (%): ≥25
Hardness: hot, ≤321HB; Cold Drawn + heat, ≤321HB
● Heat treatment and microstructure specifications:
Heat treatment specifications: quenching 870 ℃ ± 20 ℃, oil cooling; tempering 480 ℃ ± 50 ℃ (when special needs, ± 30 ℃).
Microstructure: Tempered troostite.
● Delivery status: hot-rolled steel to heat treatment or heat treatment delivery, cold drawn steel to heat treatment delivery.