● Features and Scope: good mechanical properties and process performance, high hardenability, adding vanadium steel, grain refining, reducing heat sensitivity, increased strength and toughness, high fatigue strength, yield ratio higher, but poor welding, cold plastic deformation due to low. Is a relatively high spring, as large sections of the important spring and high load operating temperature <300 ℃ valve springs, piston spring, safety valve spring ● ASTM6170 spring steel 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 Specification: 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 to heat treatment delivery ● ASTM6150 spring steel chemical composition: sulfur S ≤ 0.040, P P ≤ 0.035, chromium Cr0.80 ~ 1.10, Ni Ni ≤ 0.35, copper Cu ≤ 0.25, vanadium V0.10 ~ 0.20