30Mn2 alloy structural steel

Standard: GB / T 3077-1988
● Features and Scope:
After quenching with high strength, toughness and wear resistance, static strength and fatigue strength is good. Used as a small section of the major fasteners can be used for the frame rails, transmission gears, shafts, bolts and cold heading quality pieces of larger cross-section of the tune; mining machinery, the central intensity higher carburizing parts, such as cranes and rear axle journal and so on.
● Chemical Composition:
Carbon C: 0.27 ~ 0.34
Si Si: 0.17 ~ 0.37
Mn Mn: 1.40 ~ 1.80
Sulfur S: to allow the residual content ≤0.35
Phosphorus P: to allow the residual content ≤0.35
Chromium Cr: to allow the residual content ≤0.30
Ni: to allow the residual content ≤0.30
Cu: to allow the residual content ≤0.30
● 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): ≥63
Impact toughness αkv (J / cm2): ≥78 (8)
Hardness: ≤207HB
Sample size: Sample size is 25mm rough
● Heat treatment and microstructure specifications:
Heat treatment specifications: quenching 840 ℃, water-cooled; tempering 500 ℃, water-cooled.
● Delivery status: to heat treatment (normalizing, annealing or tempering) or without heat treatment delivery, the delivery status should be specified in the contract