고온 보일러 헤더의 잔여수명평가 사례 연구

A Case Study of Remaining Life Assessment for Boiler Header

  • 백운봉 (한국표준과학연구원 산업측정표준부) ;
  • 이해무 (한국표준과학연구원 산업측정표준부) ;
  • 박종서 (한국표준과학연구원 산업측정표준부) ;
  • 김동진 (한국표준과학연구원 산업측정표준부) ;
  • 윤기봉 (중앙대학교 기계공학부)
  • 발행 : 2001.06.27

초록

Creep-fatigue crack growth behavior was experimentally measured particularly when a crack was located in the heat affected region of 1Cr-0.5Mo steel. Load hold times of the tests for trapezoidal fatigue waveshapes were varied among 0, 30, 300 and 3,600 seconds. Time-dependent crack growth rates were characterized by the $C_t$-parameter. It was found that the crack growth rates were the highest when the crack path was located along the fine-grained heat affected zone(FGHAZ). Cracks located in other heat affected regions had a tendency to change the crack path eventually to FGHAZ. Creep-fatigue crack growth law of the studied case is suggested in terms of $(da/dt)_{avg}$ vs. $(C_t)_{avg}$ for residual life assessment.

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