24 July 2021 Spring Steel Wire
70Mn Spring Steel Bar
70MN is a high-quality carbon structural steel. The hardenability is better than that of 70# steel. After heat treatment, it can obtain better strength than 70 steel. It has overheat sensitivity and temper brittleness during heat treatment, and it is easy to produce quenching cracks. Poor cold plastic deformation ability and poor weldability.
70Mn is suitable to produce working parts under heavy stress and wear conditions, such as various spring rings, spring washers, thrust rings, locking rings, and clutch discs, used to manufacture wear-resistant and heavy-load mechanical parts, such as spring rings and spring washers , Thrust ring, clutch disc, lock ring, coil spring, etc.
Chemical Composition:
| C(％) | Si(％) | Mn(％) | P(％) | S(％) | Cr(％) | Ni(％) | Cu(%) |
|---|---|---|---|---|---|---|---|
| 0.67-0.75 | 0.17-0.37 | 0.90-1.20 | ≤0.035 | ≤0.035 | ≤0.25 | ≤0.25 | - |
Mechanical Properties:
| Yield Rp0.2 (MPa) | Tensile Rm (MPa) | Elongation A (%) | Reduction of area ψ (%): | Hardness (HB) |
|---|---|---|---|---|
| ≥ 785 | ≥ 450 | ≥ 8 | ≥ 30 | Max. 285 |