Journal of the Korean Society of Manufacturing Technology Engineers (한국생산제조학회지)
- Volume 4 Issue 4
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- Pages.42-49
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- 1995
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- 2508-5093(pISSN)
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- 2508-5107(eISSN)
Quantitative Evaluation of Fatigue Strength using a Surface defective Low Carbon Steel
저탄소강의 표면결개 방의 영향에 의한 피로강도의 정량적 평가
Abstract
It is not clearly known how defects or inclusions of a low carbon steel affect a fatigue strength. We study this issue using SM15C materials. The investigation is carried out by a quantitative evaluation, and experimental findings are: (1) a fatigue limit of A series smooth specimen is 205MPa, and that of B, C, D series is 245MPa, 304MPa and 245MPa, respectively. (2) the fatigue limit varies with respects to the stress distribution I the vicinity of a defects and crack. (3) the micro hole creates a half-circular shape crack, while the hole depth is not critical to the fatigue strength, (4) considering the fatigue strength, the hole diameter is more significant than the hole depth, and (5) Fatigue limit of artificially defected specimen is lower than that of a flawless one (5-10%), however, there exist allowance size and depth of defect which don't get to influence at fatigue limit.
Keywords
- defects and inclusions;
- quantitative evaluation;
- fatigue limit;
- micro hole;
- allowance size and depth