摘要
为了排除某航空发动机DD6镍基单晶高温合金涡轮转子叶片在室温振动试验中发生的裂纹故障,对故障叶片进行了外观检查、断口分析、表面检查、解剖检查、化学成分分析、金相检查、应力分布计算及热模拟试验,确定了故障叶片裂纹的性质和产生原因。结果表明:涡轮转子叶片裂纹为高周疲劳裂纹,叶片局部区域存在异常的γ′筏排组织是导致该叶片产生早期疲劳开裂的主要原因,且附近区域腐蚀过重及结构上处于应力集中区,也促进了疲劳裂纹的萌生及扩展。针对这些故障,建议优化叶片结构并对腐蚀检查进行严格监控,防止出现γ′筏排组织及腐蚀过重现象,从而避免此类故障再次发生。
In order to find out the crack occurred on the turbine blades that is made of DD6 single crystal superalloy applied in an aeroengine during the vibration test under the room temperature. The examination of failed turbine-blades appearance, fracture surface analysis, the examination of the original surface, the examination of the longitudinal section of the source region, chemical composition analysis, metallurgical structure analysis, calculation of stress distribution and thermal simulation test were carried out. The results show that the failure mode for the crack of failed turbine-blades is high-cycle fatigue. As a pivotal factor, abnormal γ′ rafting lead to early fatigue fracture in the localized region of the turbine-blade. Meanwhile, the fatigue crack is also influenced by serious corrosion and stress concentration. Finally in the view of the failure, it is suggested that construction of the turbine blades should be optimized and the corrosion examination process of the turbine-blades should be rigidly controlled to prevent the abnormal γ′ rafting and serious corrosion appearing,and analogous failure can be avoided.
出处
《航空发动机》
2016年第4期81-86,共6页
Aeroengine
基金
燃气轮机工程研究项目资助
