변형률제어 비대칭파형 하의 고온피로수명 및 파면

High Temperature Fatigue Life and Fractography under Asymmetric Waveform in Strain Control

  • 허정원 (안산공과대학 컴퓨터응용기계설계과) ;
  • 박원조 (경상대학교 기계항공공학부) ;
  • 유재환 (세명대학교 안전공학과)
  • 발행 : 2003.03.01

초록

In this paper, the low cycle fatigue(LCF) life tests were carried out under waveforms of asymmetric triangle($4{\times}10^{-3}$ and $4{\times}10^{-10}$ strain rate) and hold-time(1min and 10min) in strain control. In triangular waveform, the fatigue lives of fast-slow waveforms were decreased to about 63-73% and them of slow-fast waveforms were down to about 23-24% compared to them of fast-fast waveforms. The shapes of fracture surfaces were transgranular in fast-fast and fast-slow waveforms and intergranular in slow-fast ones. The fatigue lives of slow-fast waveforms were remarkedly shorter than them of hold-time waveforms even though cycle times of hold time waveforms were longer than them of slow-fast ones. The damage mechanisms of frature surfaces were mixed frature with both transgranular and intergranular, but intergranular fratures were r-type cavity in hold-time waveforms and w-type cavity in slow-fast ones.

키워드

참고문헌

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