Abstract: The main reason of low fatigue life of steel 60Si2MnA for auto stabilizing rod (/% : 0.56C, 1.74Si, 0.74Mn, 0.011P, 0.007S, 0.04Cr) is analyzed by using optical microscope, scanning electron microscope and energy dispersive spectrometer, i. e. the decarburized layer is deeper, there are cracks at surface of steel rod and the quenched structure has a lot of ferrite. With the process measures including adding 0.22% Cr in steel, adding procedure of grinding on while surface of billet and decreasing heating temperature of 150 mm x 150 mm casting billet from original 1130~1150 ℃ to 1080~1100℃ , the ferrite content in quenched steel decreases obviously, there is no crack defect on surface of steel bar and the total decarburized layer depth of φ18 mm bar decreases from original 128 μm to 87.5 μm, as a results the fatigue life of the steel increases form 6 x 10⁴~10 x 10⁴ to 20 x 10⁴~25 X 10⁴ to meet the requirement of design.

Key words: Sled 60Si2MnA for Stabilizing Rod, Suiface Quality, Decarburized Layer, Ferrite, Fatigue Life, Process Optimization

摘要： 采用金相显微镜、扫描电镜和能谱分析仪分析汽车稳定杆用钢60Si2MnA（/%:0.56C,1.74Si,0.74Mn,0.011P,0.007S,0.04Cr）疲劳寿命低的原因主要为表面脱碳层较深,表面存在裂纹,淬火组织中有较多铁素体。通过加0.22%Cr,增加连铸坯全修磨工序,150 mm×150 mm铸坯加热温度由1130~1150℃降至1080~1100℃等工艺措施显著降低了淬火后钢中铁素体含量,钢材表面无裂纹缺陷,φ18 mm棒材总脱碳层深度由原128μm降至87.5μm,使该钢的疲劳寿命由6~10万次提高至20~25万次,满足了设计要求。

关键词: 稳定杆用钢60Si2MnA, 表面质量, 脱碳层, 铁素体, 疲劳寿命, 工艺优化