24 July 2021 Mould Steel Bar
SAE4320H Mould Steel Bar
SAE4320H is a commonly used carburized alloy steel. After carburizing, the surface has high hardness, wear resistance and contact fatigue strength. At the same time, the core retains good toughness, can withstand high impact loads, and can be used as surface strengthening. Type carburized steel is used in carburized gears, carburized bearings and other parts; it can also be used after low temperature tempering, such as excavator teeth (pick teeth), agricultural machinery wear parts, etc., which require wear resistance and impact resistance. In terms of parts, it is mainly used for impact-resistant and wear-resistant parts such as railway bearings.
Chemical Composition:
| C(％) | Si(％) | Mn(％) | P(％) | S(％) | Cr(％) | Ni(％) | Mo(％) | Cu(%) |
|---|---|---|---|---|---|---|---|---|
| 0.17～0.23 | 0.15～0.40 | 0.40～0.70 | ≤0.030 | ≤0.030 | 0.35～0.65 | 1.60~2.00 | 0.20～0.30 | ≤0.30 |
Mechanical Propoerties:
| Yield Strength Rp0.2(MPa) | Tensile Strength Rm(MPa) | Impact Energy KV(J) | Elongation at Fracture A(%) | Reduction in Cross Section on Fracture Z(%) | As-Heat-Treated Condition | Brinell Hardness(HBW) |
|---|---|---|---|---|---|---|
| ≥ 780 (100) | ≥ 980 (100) | ≥78(8) | ≥13 | ≥45 | Solution and Aging,Annealing,Ausaging,Q+T,etc | 429 |
Heat Treatment Specification and Metallographic Organization:
Heat treatment specifications: quenching, the first 880 ± 20 °C, the second 800 ± 20 °C, oil cooling; tempering, 150 ~ 200 °C, air cooling.
Microstructure: Carburized layer is high carbon martensite. The heart is low carbon martensite.