The 60Si2MnA alloy element content, the hardenability 60Si2Mn high, higher toughness plastic, decarburization tendency of small, good tempering stability, thermal processing performance and low cost. Spring steel 60si2mna, manganese improve the hardenability, φ12 mm steel oil can hardenability, surface decarburization tendency smaller than silicon, the mechanical properties after heat treatment is better than carbon steel, but the thermal sensitivity and temper brittleness 
 . Instead 60Si2MnA the production of heavy, medium and small cars leaf springs and other medium-sized section of the leaf spring and coil spring. 60Si2MnA strength and hardness. Flexibility and hardenability than the No. 65 steel, with a thermal sensitivity and tendency to temper brittleness, water quenching the formation of the crack tendency. Annealed machinability can still be cold deformation plasticity, poor weldability. Under moderate load plate spring, 7-20mm diameter coil spring and spring washer spring ring. High wear resistance parts, such as the grinding machine spindle. Spring chuck precision machine screw. Cutter. Spiral roller bearing ring. Railway rail and so on. 

 Chemical composition 
 Carbon, the C: 0.52 ~ 0.60 Si Si: 1.5 ~ 2.0 Mn Mn: 1.00 ~ 1.30 SS: ≤ 0.035 phosphorus P: ≤ 0.035 Chromium Cr: ≤ 0.35 Ni - Ni: ≤ 0.35 Copper Cu: ≤ 0.25 vanadium V: 0.08 ~ 0.16 boron B: 0.0005 ~ 0.0035 

 Mechanical properties 
 Tensile strength σb (MPa): ≥ 1372 (140) yield strength σs (MPa): ≥ 1225 (125) δ10 of elongation (%): ≥ 5 Reduction of the rate of ψ (%): ≥ 30 Hardness: hot, ≤ 321HB; Cold Drawn + heat treatment, ≤ 321HB 

 Heat treatment and microstructure 
 Specification of heat treatment: quenching 860 ° C ± 20 ° C, cold oil; tempering 460 ° C ± 50 ° C (special needs, ± 30 ° C). Microstructure: tempering sorbitic. AC1, 755, Ac3-770, Ms.-300 305, annealing; 750C,-cold-HBS was ≤ 222 normalizing furnace; 830 ~ 860C-air-cooled-HBS was ≤ 302 quenching; 870C-oil-of HRC> 61 different temperatures after tempering hardness value of HRC: 150C-61 200C-60 300C-56 400C-51 500C-43 550C-38 600C-33 650C-29 commonly used tempering temperature of 430 to 480C, water or air, HRC45 ~~ 50 

 Quenching heat insulation thickness: mm / min, 6.5 / 2,8 / 3,8.5-10 / 4,12 / 5 tempering holding time and thickness: mm / min, and <10/25-30, 10 - 15/30-35 ,15-20 / 40-45,20-25 / 45-50.