Material Name: Alloy structural steel
Grade: 20CrMnSi
Standard: GB / T 3077-1988
● Features and Scope:
Are both high strength and toughness of low-carbon steel, with a repeated impact resistance, good low temperature impact toughness and wear resistance, higher ductility and good weldability. Suitable for the manufacture of cold-drawn or cold stamping parts and welding parts require a higher, higher toughness can also be manufactured parts, such as high intensity mining ring chain, high strength bolts.
● Chemical Composition:
Carbon C: 0.17 ~ 0.23
Si Si: 0.90 ~ 1.20
Mn Mn: 0.80 ~ 1.10
Sulfur S: to allow the residual content ≤0.035
Phosphorus P: to allow the residual content ≤0.035
Chromium Cr: 0.80 ~ 1.10
Ni: to allow the residual content ≤0.030
Cu: to allow the residual content ≤0.030
● Mechanical Properties:
Tensile strength σb (MPa): ≥785 (80)
Yield strength σs (MPa): ≥635 (65)
Elongation δ5 (%): ≥12
Reduction of ψ (%): ≥45
Impact energy Akv (J): ≥55
Impact toughness αkv (J / cm2): ≥69 (7)
Hardness: ≤207HB
Sample size: Sample size is 25mm rough
● Heat treatment and microstructure specifications:
Heat treatment specifications: quenching 880 ℃, oil cooling; tempering 480 ℃, water, oil cooling.
Microstructure: sorbite + acicular ferrite.
● Delivery status: to heat treatment (normalizing, annealing or tempering) or without heat treatment delivery, the delivery status should be specified in the contract.