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随着对汽车轻量化和安全性要求的不断提高,改善疲劳性能成为弹簧钢研究与开发的一个重要主题。在Amsler HFP 5000高频疲劳试验机上研究了弹簧钢55SiCrA轴向拉-压加载的疲劳性能,测定了其条件疲劳极限及S-N曲线,利用扫描电镜(SEM)和E-DAX对疲劳断口及夹杂物进行观察,对断口进行了宏观和微观分析,研究了疲劳破坏的机制。试验结果表明:试验钢的条件疲劳极限为820 MPa,σ-1p/σb=0.562(Nf=107);疲劳裂纹源主要起源于表面,较大的夹杂物(20~30μm)也成为疲劳裂纹源;疲劳裂纹稳定扩展区的疲劳条带宽度为1.5~2.0μm。
As the demand for lightweight and safety of vehicles continues to improve, improving fatigue performance has become an important topic for spring steel research and development. The fatigue properties of 55SiCrA spring loaded steel under axial tension-compression loading were investigated on an Amsler HFP 5000 high-frequency fatigue testing machine. The fatigue limit and SN curve were measured. SEM and E-DAX were used to measure the fatigue fracture and inclusions The observation was made. The fracture was analyzed macroscopically and microscopically, and the mechanism of fatigue failure was studied. The results show that the fatigue limit of the test steel is 820 MPa and the σ-1p / σb = 0.562 (Nf = 107). The source of the fatigue crack mainly originates from the surface and the larger inclusions (20-30 μm) also become the sources of fatigue cracks The fatigue band width of fatigue crack growth area is 1.5 ~ 2.0μm.