机械轴承用SUJ2钢的裂纹扩展机制分析

Crack Propagation Mechanism of Steel SUJ2 Used for Machinery Bearing

研究了轴承用SUJ2钢断口处GBF(granular bright facet)裂纹的扩展机制。结果表明,当应力幅值增加时GBF尺寸下降,且当应力幅值不变时GBF尺寸也保持不变。当夹杂物的尺寸变大时其疲劳寿命Nf下降。在疲劳初期形成GBF,当循环次数增加时,GBF尺寸基本保持不变,直到最终的疲劳断裂。

The propagation mechanism the GBF（granular bright facet） crack at the fracture sites of the steel SUJ2 used for bearing was investigated. The results show that the GBF size decreases with the increase of the stress amplitude, and GBF size is stable when the stress amplitude is not changed. The fatigue life Nf decreases with the increase of the inclusion size.In the initial, the GBF forms and its sizes are unchanged when the cycles is increased, even the cycles is increased to the ultimate fatigue fracture.