发动机架圈裂纹故障分析

Failure Analysis of Bobbin in Aero-engine

发动机架圈在大修分解检查中发现耳片与圈体之间的焊缝熔合区存在裂纹,结合架圈的使用条件,通过裂纹分布与形貌分析、断口特征观察、硬度测试、化学成分分析和组织检查等方法,分析了裂纹产生的原因。研究结果表明:架圈裂纹为高周疲劳裂纹;焊接缺陷、零件表层氧化脱碳及载荷分布不均匀造成疲劳裂纹集中分布在应力较大的架圈耳片焊接接头熔合区是疲劳裂纹产生的原因。

While an aircraft engine was overhauled, the bobbin was found to have some cracks in the fusion zone of weld between the pipe line and the auricle. In order to find out the failure cause, macro and micro observation, hardness testing, chemical composition analysis and microstructure examination were carried out. The results show that the cracks of the bobbin are high- cycle fatigue cracks. Weld defects, surface oxidation-decarburation and uneven load distribution resulted in fatigue cracking in the fusion zone of the welded joint of the auricle where stress was greater.