- 고온하 304 스테인리스철의 표면규열의 성장거동에 관한 실험적 연구
- ㆍ 저자명
- 서창민,신형섭,황남성,정대윤
- ㆍ 간행물명
- 韓國海洋工學會誌
- ㆍ 권/호정보
- 1995년|9권 1호|pp.63-72 (10 pages)
- ㆍ 발행정보
- 한국해양공학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
The crack which is discovered in various structures and machine elements is multi-cracks. Multi-cracks may cause serious problems because they grow individually, and coalesce into one and it leads to fracture. Fatigue tests have been carried out to study the growth and coalescence behavior of multi-surface-cracks initiated at the semicircular surface notch in type 304 stainless steel at elevated temperature. The results are as follows; When multi-surface-cracks are lying on the surface of material, the major surface crack has greater influence on the fatigue life than the subcracks. The aspect ratio of multi-surface-cracks is lower than that of single crack because of the interaction and coalescence of surface cracks. Crack growth shape turns to semiellipse from the semicircle notch. After coalescence, the surface crack length increases rapidly, and it leads to fracture. Further, the slope transition of Paris law was found in the da/dN-$Delta$K$_1$ plots.