含表面缺陷扭力轴的断裂失效分析

Fracture Failure Analysis of Torsion Bar with Surface Defects

通过扫描电子显微镜和 X 射线能谱仪对某型履带车辆含表面缺陷扭力轴的正断型断口进行了失效分析,结果表明,扭力轴的断裂属于早期低周疲劳断裂,裂纹起源于扭力轴表面的微损伤,冶金过程中产生的微观孔洞和夹杂聚集于扭力轴表面及次表面影响了裂纹的扩展方向并形成了特殊的微观特征。在此基础上,分析了表面缺陷使疲劳寿命降低的原因,对扭力轴的生产、使用和维修提出了建议。

Scanning electronic microscope (SEM) and X-ray energy dispersive analysis (EDX) were used to investigate fatigue failure of the torsion bar with surface defects of a tracked vehicle, results show that the crack initiation at surface and propagation of the crack were influenced by accumulated residue stress at the surface and sub-surface. The reasons of life decline of torsion bar with defect were analyzed and some advices were given to the process of manufacture and maintenance.