24 July 2021 Spring Steel Wire
55SI2Mn Spring Steel Wire
55Si2Mn spring steel, due to add silicon and manganese, it improve its elastic strength and yield strength, improve hardenability, anti-tempering stability and anti-relaxation stability, and have less sensitivity to overheating, but have a greater tendency to decarburize, especially the content of silicon and carbon at higher levels, carbon is easy to graphitize, making steel brittle. 55Si2Mn spring steel is used as damping leaf spring and coil spring on automobiles, tractors and locomotives, cylinder safety valve spring, and can also be used as heat-resistant springs below 250°C.
Chemical Composition:
| C | Si | Mn | S | P | Cr | Ni | Cu |
|---|---|---|---|---|---|---|---|
| 0.52~0.60 | 1.50~2.00 | 0.60~0.90 | ≤0.035 | 0.035 | ≤0.35 | ≤0.35 | ≤0.25 |
Mechanical properties：
| Tensile Strength σb (MPa): | Yield Strength σ0.2 (MPa): | Elongation δ5 (%): | Section shrinkage ψ (%): | Hardness: |
|---|---|---|---|---|
| 1450~1750 | 1300 | ≥ 6 | ≥30 | Hot Rolled: ≤ 302HB Cold Rolled + Heat Treatment: ≤ 321 HB |
Heat treatment specification:
Quenching 870℃±20℃, oil cooling; tempering 480℃±50℃ (for special needs, ±30℃).
Delivery status:
Hot-rolled steel is delivered in heat-treated or non-heat-treated state, and cold-drawn steel is delivered in heat-treated state.