Executive Standard: JIS G4801-2005
China Standard: GB / T 3077-1999
American Standard: A29M: 2005
● Features and application:
Good mechanical properties and process performance, high hardenability, adding vanadium to steel the grain refinement, reduce heat sensitivity, increased strength and toughness, high fatigue strength, yield ratio is high, but poor welding cold plastic deformation due to the low. Is a relatively high spring, as a large section of the important spring and high-load operating temperature <300 ℃ of the valve spring, piston spring, valve spring.
● Chemical Composition:
Carbon C: 0.47 ~ 0.55
Si Si: 0.15 ~ 0.35
Manganese Mn: 0.65 ~ 0.95
Sulfur S: ≤ 0.030
Phosphorus P: ≤ 0.030
Chromium Cr: 0.80 ~ 1.10
Ni-Ni: ≤ 0.35
Copper Cu: ≤ 0.25
Vanadium V: 0.15 ~ 0.25
● Mechanical Properties:
Tensile strength σb (MPa): ≥ 1274 (130)
Yield strength σs (MPa): ≥ 1127 (115)
Elongation δ5 (%): ≥ 10
Reduction of area ψ (%): ≥ 40
Hardness: hot, ≤ 321HB; cold-drawn + heat treatment, ≤ 321HB
● Heat treatment and microstructure specifications:
Standard heat treatment: quenching 850 ℃ ± 20 ℃, oil cooling; tempering 500 ℃ ± 50 ℃ (special needs, ± 30 ℃).
● Delivery status: hot-rolled steel to heat treatment or heat treatment delivery, cold-drawn steel with heat treatment delivery.
