24 July 2021 Structural Steel Bar
21CrMoV5-7 Structural Steel Bar
21CrMoV5-7 is structural steel with specified high temperature and low temperature properties. Equivalent to DIN 1.7709 , it is designed for nitriding, giving similar hardness distribution as case hardening. When using nitriding the distortion due to quenching after carburising can be avoided.
21CrMoV5-7 is pearlite heat-resistant steel, which has high thermal strength (δb≥440MPa) and oxidation resistance at high temperature and has certain resistance to hydrogen corrosion. As the steel contains a higher content of Cr, C and other alloying elements, steel tend to harden more obvious, poor weldability.
Chemical Composition:
| C(％) | Si(％) | Mn(％) | P(％) | S(％) | Cr(％) | Mo(％) | V(％) |
|---|---|---|---|---|---|---|---|
| 0.17～0.25 | 0.15 ~ 0.35 | 0.35 ~ 0.85 | ≤0.035 | ≤0.030 | 1.20～1.50 | 0.65 ~ 0.80 | 0.25 ~ 0.35 |
Mechanical Propoerties:
| Yield Strength Rp0.2(MPa) | Tensile Strength Rm(MPa) | Elongation δ5 (%): | Reduction of area ψ (%): | Absorbed work DVM, J: | Modulus of elasticity, N/mm²: | Hardness |
|---|---|---|---|---|---|---|
| ≥ 550(65) | ≥ 850(85) | ≥ 16 | ≥ 60 | ≥ 63 | ≥ 211 | ≥ 235 HB |
Heat treatment:
890-940℃ quenching, 680-720℃ high temperature tempering (at least 2h)