半挂车车轴轴头断裂原因分析

Fracture Analysis of Trailer Axle

对断口、成分和显微组织进行了检测,分析半挂车车轴轴头在装配、校准中出现的断裂现象。结果表明,车轴轴头原材料中存在疏松、缩孔残余等内部冶金缺陷和锻造热加工中的过热和过烧产生不良的魏氏组织,这些因素的综合作用致使钢的韧性降低,在锻造中发生内部劈裂,最终造成轴头在受外力时脆性断裂。

The fracture,composition, microstructure of trailer axles was tested by means of SEM and EDS, the abnormal fracture during assembling and calibrating was analyzed. The experimental results show that there are some internal metallurgy flaws such as looseness, shrink hole in the raw material of the axle, and bad widmanstatten structure from the overheating and over-burning during the heating of forging, the comprehensive effects of these factors cause the steel toughness to reduce, and the internal cleavage exists during forging. Finally, the trailer axle becomes broken when outside force is exerted.