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(%)
0.17~0.250.15 ~ 0.350.35 ~ 0.85≤0.035≤0.0301.20~1.500.65 ~ 0.800.25 ~ 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)

 

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