航空学报 > 1994, Vol. 15 Issue (8): 960-967

孔挤压强化对两种超高强度钢疲劳裂纹起始与扩展寿命的影响

丁传富, 赵振业, 宋德玉   

  1. 北京航空材料研究所25室,北京,100095
  • 收稿日期:1992-10-28 修回日期:1993-07-25 出版日期:1994-08-25 发布日期:1994-08-25

EFFECT OF COLDWORKED HOLES ON THE INIATION LIFE AND PROPAGATION LIFE OF FATIGUE CRACKS IN TWO ULTRA-HIGH STRENGTH STEELS

Ding Chuanfu, Zhao Zhenye, Song Deyu   

  1. Department 25,Beijing Institute of Aeronautical Materials,Beijing,100095
  • Received:1992-10-28 Revised:1993-07-25 Online:1994-08-25 Published:1994-08-25

摘要: 采用挤压和非挤压的中心孔试样研究了300M和30CrMnSiNi2A两种超高强度钢在随机载荷谱加载条件下的疲劳裂纹起始和扩展寿命。试验结果表明,孔冷挤压显著提高两种超高强度钢的疲劳飞行寿命。经SEM观察,挤压件的疲劳源产生于孔用处,为单疲劳源;未挤压件的疲劳源大多起始于孔壁表面,为多疲劳源。

关键词: 冷硬化, 频谱分析, 残余应力, 裂纹初始, 裂纹扩展

Abstract: The effect of coldworked holes on the initiation life and growth life offatigue cracks in two ultra-high strength steel plate specimens,300M and 30CrMnSiNi2A steels,under the flight spectrum loading for wing root is investigated.The experimental results show that the coldworked holes significantly extend the fatigue life of ultra-high strength steel.However,on-ly crack growth life is noticeably affected and no obvious effect is observed on the initiation un- der the present process of coldworking.A SEM study indicates that the fatigue sourees for coldworked and unworked specimens initiated at the corner of the holes and the surfaee of hole bore respectively;the former is only single fatigue source while the latter is multiple source.

Key words: Key words cold hardening, spectrum analysis, residual stress, crack initiationpropagaUoncrack

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