U.S. the Fen Coke 6150 spring steel 
 Chemical composition: 
 Carbon, the C: 0.46 to 0.54 Si Si: 0.17 ~ 0.37 Mn Mn: 0.50 ~~ 0.80 sulfur S-: ≤ 0.030 P: ≤ 0.030 Chromium Cr: 0.80 ~ 1.10 Ni - Ni: ≤ 0.35 Copper Cu: ≤ 0.25 vanadium V: 0.10 ~~ 0.20 
 6150 mold steel Features and Scope: 
 Good mechanical and technological properties, hardenability higher, adding vanadium steel grain refinement to reduce the thermal sensitivity, improved strength and toughness, high fatigue strength, yield a higher ratio, but the poor weldability , cold deformation plasticity. A higher spring, as a larger cross-section of high load spring and the operating temperature <300 ° C the valve spring, piston spring, the relief valve spring 
 6150 mold steel mechanical properties: 
 Tensile strength σb (MPa): ≥ 1274 (130) 
 Yield strength σs (MPa): ≥ 1127 (115) 
 Elongation δ5 (%): ≥ 10 
 Section shrinkage ψ (%): ≥ 40 
 Hardness: hot, ≤ 321HB; Cold Drawn + heat treatment, ≤ 321HB 
 Heat treatment and microstructure: 
 Specification of the heat treatment: quenching 850 ° C ± 20 ° C, cold oil; tempering 500 ° C ± 50 ° C (special needs, ± 30 ° C). 
 6150 mold steel delivery status: 
 Hot-rolled steel to heat treatment or heat treatment condition, delivery, cold drawn steel to heat treatment delivery.