刘军和,巩孟祥,魏涛,曹家洺.航空发动机离子火焰探测器探管裂纹故障分析[J].航空发动机,2021,47(S1):64-68
航空发动机离子火焰探测器探管裂纹故障分析
Analysis on Crack Failure of Ion Flame Detector of Aeroengine
  
DOI:
中文关键词:  焊缝裂纹  故障分析  离子火焰探测器  探管  航空发动机
英文关键词:crack of weld seam  failure analysis  ion flame detector  probe tube  aeroengine
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作者单位E-mail
刘军和,巩孟祥,魏涛,曹家洺 空军装备部驻沈阳地区第二军事代表室沈阳110043 279905525@qq.com 
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中文摘要:
      某航空发动机试车后连续出现2起离子火焰探测器探管根部焊缝处裂纹故障,为查明故障原因,从外观检查、断口分 析、产品结构、加工过程等方面进行分析,确定了探管裂纹为疲劳裂纹,经分析确定2件故障产品焊缝处疲劳裂纹产生的原因分别 为:焊探管时2次手工氩弧焊堆焊时送丝速度不均匀造成焊趾凹凸不平;焊趾处为探管端熔合线,引起应力集中、探管材料表面存 在突起物造成。在发动机试车时,离子火焰探测器探管在热冲击、振动等交变应力作用下,从探管强度薄弱部位形成疲劳源,最终 导致裂纹沿径向贯穿探管壁厚,沿圆周方向继续扩展产生疲劳断裂。提出了明确焊缝表面形状、保证填料位置和速度、增加抛光 后荧光检查、增加探管焊缝放大镜检查、外场普查等预防和改进措施。
英文摘要:
      There were two consecutive cracks at the root weld of the probe tube of the ion flame detectorafter the test run of an aeroen? gine. In order to find out the cause of the fault,the appearance inspection,fracture analysis,product structure and processing process were analyzed and the crack of the probe tube was determined as fatigue crack.After analysis,the causes of fatigue cracks at the weld joint of the two faulty products were determined as follows:uneven wire feeding speed during two times of manual argon arc welding and overlay? ing welding,resulting in uneven weld toe. The weld toe was the fusion line at the end of probe pipe,which caused stress concentration and protrusion on the surface of probe pipe. During the engine test,the probe tube of ion flame detector formed fatigue source from the weak part of the probe tube under the action of alternating stress such as thermal shock and vibration,which eventually caused the crack to pene? trate the wall thickness of the probe tube along the radial direction and continued to expand along the circumferential direction,resulting in fatigue fracture. Some preventive and improvement measures are put forward,such as defining the shape of weld surface,ensuring the position and speed of filler,increasing the fluorescence inspection after polishing,increasing the magnifying glass inspection of probe pipe weld,field survey and so on.
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