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本文主要研究了三种不同方向的刻槽(轴向、螺旋、环形)试样,在旋转弯曲、拉一压、拉压—扭转组合及扭转四种疲劳载荷下的断裂机制及对车轴钢疲劳强度的影响规律,轴向刻槽影响甚微,环形刻槽(除旋弯疲劳)影响最大,疲劳极限最低。旋弯疲劳下,螺旋刻槽影响最大。 本文还进一步对光滑及环形刻槽试样的旋转弯曲疲劳断口形貌进行分析。SEM观察表明:车轴钢疲劳裂纹扩展第1阶段特征为循环解理刻面,属于滑移剪切型裂纹萌生机制。
In this paper, three different directions of notch (axial, helical, annular) specimens were studied, and the fracture mechanism and the fatigue of axle steel under four kinds of fatigue loads of rotation bending, tensioning and drawing, The influence of strength, axial groove has little effect, ring groove (except spin fatigue) the greatest impact, the lowest fatigue limit. Spiral fatigue, spiral groove the greatest impact. In this paper, we further analyze the rotating and bending fatigue fracture surfaces of smooth and annular grooved specimens. SEM observations show that the first stage of fatigue crack growth of axle steel is characterized by cyclic cleavage facets, belonging to the mechanism of slip shear-type crack initiation.