Analysis on Head Shedding off from Rivet of Turbine
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摘要: 涡轮冷却器返厂检查时发现，涡轮上的1个铆钉头已经断裂、脱落；经荧光无损探伤检查发现其他一些铆钉在铆钉头与铆钉杆相接的转角R处仍存有裂纹。本研究通过对断口、硬度、化学成分、金相组织等理化检测手段，并结合涡轮结构和使用工况，对涡轮铆钉头脱落原因进行分析。结果表明：铆钉的断裂性质属于微动疲劳；涡轮结构明显存在被铆接件较薄、且硬度远高于铆钉的设计缺陷；铆钉头脱落的主要原因可能与涡轮结构设计不合理及选材不当有关。采用优化涡轮结构、选取抗疲劳强度更佳的铆钉等措施可以预防类似故障再次发生。Abstract: A rivet head was found to have shed off from the turbine during the return check. Cracks were also found in the head R angles of some other rivets by means of fluorescence penetrant inspection. In this paper, the cause of rivet head shedding off from turbine was analyzed by means of fracture observation, hardness testing, chemical composition analysis and metallographic examination. The turbine structure and working condition were also considered. The results show that the fracture mode is fretting fatigue fracture. The turbine structure has obvious design deficiency:the riveted part is thin and its hardness is much higher than that of the rivet. The fretting fatigue fracture of rivet is related to design deficiency and material selection. Such measures as improving structure and selecting suitable rivet material can effectively prevent such failure.
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Keywords:
- rivet /
- fretting fatigue /
- turbine /
- shedding off
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[1] 张栋,钟培道,陶春虎,等. 失效分析[M]. 北京:国防工业出版社,2008:243-244. [2] 伍曾,李洁青,黄伟,等. 微动磨损对弹条Ⅱ型扣件弹条断裂的影响分析[J]. 昆明理工大学学报:自然科学版,2013,38(6):43-47. [3] 陶春虎. 紧固件的失效分析及其预防[M]. 北京:航空工业出版社,2013:25-26. [4] Wang R Z, Ru J L. Overall evaluation of the effect of residual stress induced by shot peening in the improvement of fatigue fracture resistance for metallic materials[J]. Chinese Journal of Mechanical Engineering,2015,28(2):416-421.
[5] 邓成江,何晓聪,邢保英,等. 基于试验的自冲铆接失效机理分析[J]. 热加工工艺,2013,42(17):220-223. [6] Chan W L, Yang Y, Wei H Y, et al. Analysis on fatigue for aircraft riveting thin-walled components[J]. Applied Mechanicals and Materials,2012,246-247:122-126.
[7] 贺孝涛,叶新农. 发动机轴承保持架铆钉头脱落原因分析[J]. 失效分析与预防,2013,8(1):55-59. [8] 张立君,吴细毛,孙笑. 800MW汽轮机高压转子围带脱落原因分析及处理[J]. 东北电力技术,2004,25(11):7-9. [9] 王仁智,汝继来,李向斌,等. 疲劳裂纹萌生的微观过程和内部疲劳极限理论[J].金属热处理学报,1995,16(4):26-34. [10] 陈永富,陈兰芳. 飞机环控涡轮冷却器轴承壳体制造工艺研究与应用[J]. 航空精密制造技术,2005,41(4):40-42. [11] 陈星,刘松,姜涛. 进油嘴设计不合理引发涡轮冷却器失效分析[J]. 失效分析与预防,2013,8(2):117-122. [12] 刘松. 铝合金叶轮共振振型的研究[J]. 失效分析与预防,2011,6(4):224-228.
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