Journal of the Korean Society for Heat Treatment (열처리공학회지)
- Volume 14 Issue 4
- /
- Pages.212-219
- /
- 2001
- /
- 1225-1070(pISSN)
- /
- 2508-4046(eISSN)
Fatigue Characteristics and its Nondestructive Evaluation of Fire-resistance Steel for Construction with Low Yield Ratio and High Strength
저항복비·고강도 구조용 내화강의 피로특성 및 비파괴평가
- Kim, H.S. (Division of Materials Science and Engineering, Pukyong National University) ;
- Nam, K.W. (Division of Materials Science and Engineering, Pukyong National University) ;
- Kang, C.Y. (Division of Materials Science and Engineering, Pukyong National University)
- Published : 2001.07.31
Abstract
The fatigue test was carried out to evaluate the fatigue characteristics of fire resistance steel for frame structure and heat affected zone (HAZ) by the one side Gas Metal Arc Welding (GMAW). In this paper, the fatigue crack growth behavior was investigated with the compact tension specimen of base metal and the HAZ according to chemical composition and rolling end temperature, respectively. And the acoustic emission signals obtained from the fatigue test were analyzed by the time-frequency analysis method as a nondestructive evaluation. Main results obtained are summarized as follows; The hardness was appeared softening phenomenon that weld metal and HAZ are lower than that of base metal. Fatigue life of welded specimen was longer than that of base metal. m was 3~4.5 in base metal and 3.8~5.8 in HAZ. The main frequency range of acoustic emission signal analyzed from time-frequency method is different with the range by noise and crack. Also, it could be classified that it was also generated by fracture mechanics of dimple, inclusion etc.
Keywords
- Fire resistance steel for frame structure;
- Fatigue Crack propagation rate;
- Gas metal arc welding;
- Heat affected zone(HAZ);
- Weld metal;
- Time frequency analysis;
- Acoustic emission