85 Gang Material Name: spring steel Standard: GB / T1222-2007 Features and Scope: 85 # steel strength, hardness than other high-carbon structural steel to be high, but slightly lower elasticity, its revenue performance and 65,70,75 80 steel were similar, not high hardenability, the critical quenching in oil diameter of 9-23mm. No. 85 steel for the manufacture of small cross-sectional size and strength to withstand vibration spring is not too high, such as railway vehicles, cars, tractors and general machinery, flat springs and round on the coil spring, and for other purposes, such as spring steel wire and steel. The highest carbon content of high-carbon structural steel, strength hardness than other high-carbon steel, but slightly elastic elastic slightly ,, but other properties 65.70.75.80 steel phase approximation. Hardenability is not high. Railway vehicles flat plate spring. Circular spiral spring steel wire. Steel and so on. 2 Chemical composition Chemical Composition: Carbon C: 0.82 ~ 0.90 Si Si: 0.17 ~ 0.37 Mn Mn: 0.50 ~ 0.80 Sulfur S: ≤0.035 phosphorus P: ≤0.035 chromium Cr: ≤0.25 Ni Ni: ≤0.25 copper Cu: ≤0.25 3 Mechanical Properties Mechanical Properties: Tensile strength σb (MPa): ≥1127 (115) yield strength σs (MPa): ≥980 (100) Elongation δ10 (%): ≥6 section shrinkage ψ (%): ≥30 Hardness: Hot ≤302HB; Cold Drawn + heat ≤321HB; annealed steel ≤255 hardness HBS: No heat ≤269; annealed steel ≤229, sample blank size: 25mm blank sample size / mm: Sample Heat treatment and gold phase: Heat treatment specifications: quenching 820 ℃ ± 20 ℃, oil cooling; tempering 480 ℃ ± 50 ℃ (when special needs, ± 30 ℃). Delivery status: hot-rolled steel to heat treatment or heat treatment delivery, cold-drawn steel to heat treatment delivery.