| Quantity: | |
|---|---|
CHEMICAL COMPOSITION
C: About 0.57% - 0.65%
Cr: about 1.0% - 1.3%
Mn: about 0.90% - 1.20%
Si: usually low, ≤0.40%
P and S: Strictly controlled at lower levels.
MECHANICAL PROPERTIES
Tensile strength (σb): ≥675 MPa (69 kgf/mm²)
Yield strength (σs): ≥400 MPa (41 kgf/mm²)
Elongation (δ5): ≥12%
Area shrinkage (ψ): ≥35%
Hardness: hardness without heat treatment ≤255 HB; hardness of annealed steel ≤229 HB
HEAT TREATMENT
Normalizing: Heating to a certain temperature, keeping warm, and then cooling to improve the organizational structure.
Quenching: Rapid cooling after heating to increase hardness.
Tempering: Heat treatment performed after quenching to reduce internal stress and improve toughness.
CHEMICAL COMPOSITION
C: About 0.57% - 0.65%
Cr: about 1.0% - 1.3%
Mn: about 0.90% - 1.20%
Si: usually low, ≤0.40%
P and S: Strictly controlled at lower levels.
MECHANICAL PROPERTIES
Tensile strength (σb): ≥675 MPa (69 kgf/mm²)
Yield strength (σs): ≥400 MPa (41 kgf/mm²)
Elongation (δ5): ≥12%
Area shrinkage (ψ): ≥35%
Hardness: hardness without heat treatment ≤255 HB; hardness of annealed steel ≤229 HB
HEAT TREATMENT
Normalizing: Heating to a certain temperature, keeping warm, and then cooling to improve the organizational structure.
Quenching: Rapid cooling after heating to increase hardness.
Tempering: Heat treatment performed after quenching to reduce internal stress and improve toughness.
