摘要
采用化学成分,宏观断口形貌,微观组织等方法对某大客车转向机构摇臂轴的断裂进行分析.结果表明:断裂的原因是未按图纸要求用材,更主要的是调质热处理不当,调质组织不是正常的回火索氏体组织,存在较多趋网状分布的铁素体组织,硬度偏低.此外,轴肩过渡圆弧加工质量欠佳和结构刚性突变,产生较大的应力集中,在交变弯曲载荷作用下,导致摇臂轴多源双向弯曲疲劳断裂.
The present paper performs failure analysis of the fixed-pivot shaft of a coach steering mechanism. The results showed that the fixed-pivot shaft failure mainly belonged to using steel that was not assigned by the designing drawing and the improper heat treatment of quenching and tempering. The microstructure obtained after the quenching and tempering treatment was not the normal tempered sorbite but tempered sorbite with considerable amount of network-distributed ferrite, resulting in the lower hardness. In addition, the stress concentration due to the imprecisely controlled machining and the sudden change of the stiffness in the structure, and the alternating load also contributed to the multi-source biaxial bending fatigue fracture of the fixedpivot shaft.
出处
《厦门理工学院学报》
2007年第1期21-25,共5页
Journal of Xiamen University of Technology
关键词
大客车
转向机构
断裂分析
疲劳断裂
热处理
automotive
steering mechanism
failureanalysis
fatigue fracture
heat treatment
