• 제목/요약/키워드: ${\Delta}{\cdot}k_{eff}$

검색결과 1건 처리시간 0.013초

산성안개 환경하에서 Ni-Cr-Mo 강의 피로크랙전파거동 (Fatigue Crack Growth Behavior of Ni-Cr-Mo Steel under Acid Fog Environment)

  • 김민건;임용호;김만구
    • 대한기계학회논문집A
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    • 제24권7호
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    • pp.1841-1846
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    • 2000
  • To examine the effect of acid fog on the corrosion fatigue behavior in structural steel, fatigue tests under acid fog atmosphere were carried out in comparison with distilled water. The corrosive c omponents contained in acid fog pile up the corrosion products on crack face and show a crack branching and crack tip blunting. Therefore, due to these workings crack growth rate was reduced by decreasing the effective stress range in crack tip rather than under distilled water. Also the effect of sulfuric acid, which is the main component of acid fog, and testing speed on fatigue crack growth were examined. It was found that corrosion behavior was remarkably dependent upon pH and Hz rather than components of acid fog. According as pH and testing speed decrease below a specific value, crack growth was accelerated in comparison with distilled water. This reveals that due to liquid having strong acidity and slow speed of test the crack face dissolution was promoted, so crack closure was disturbed in the process of stress descent.