55Si2MnB spring steel
Standard: GB / T 1222-1984
● Features and application:
And 55Si2Mn similar properties and uses, as adding small amounts of boron, so that a higher hardenability, but also improve the fatigue strength, longer service life. For the manufacture of medium and small cross-section of the leaf spring.
● Chemical Composition:
Carbon C: 0.52 ~ 0.60
Si Si: 1.50 ~ 2.00
Manganese 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
Boron B: 0.0005 ~ 0.004
● Mechanical Properties:
Tensile strength σb (MPa): ≥ 1274 (130)
Yield strength σs (MPa): ≥ 1176 (120)
Elongation δ10 (%): ≥ 6
Reduction of area ψ (%): ≥ 30
Hardness: hot, ≤ 321HB; cold drawing heat treatment, ≤ 321HB
