Korean Journal of Metals and Materials (대한금속재료학회지)

The Korean Institute of Metals and Materials (대한금속재료학회)
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Estimation for the Distribution of Creep Crack Growth Coefficients by Probabilistic Assessment

확률적 방법에 의한 크리프 균열성장 계수의 분포 추정

  • Lee, Sang-Ho (Division of Information Statistics, Kangnung National University) ;
  • Yoon, Kee-Bong (Mechanical Engineering, Chung-Ang University) ;
  • Choe, Byung-Hak (Department of Metal & Materials Engineering, Kangnung National University) ;
  • Min, Doo-Sik (Department of Metal & Materials Engineering, Kangnung National University) ;
  • Ahn, Jong Seok (Korea East-West Power Co. LTD) ;
  • Lee, Gil Jae (Korea East-West Power Co. LTD) ;
  • Kim, Sun-Hwa (Advansed Metal & Materials Engineering, Soonchunhyang University)
  • 이상호 (강릉대학교 정보통계학과) ;
  • 윤기봉 (중앙대학교 기계공학과) ;
  • 최병학 (강릉대학교 금속재료공학과) ;
  • 민두식 (강릉대학교 금속재료공학과) ;
  • 안종석 (한국동서발전(주) 연구개발팀) ;
  • 이길재 (한국동서발전(주) 연구개발팀) ;
  • 김선화 (순천향대학교 신소재공학과)
  • Received : 2009.11.04
  • Published : 2010.09.22
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Abstract

The creep crack growth rate (da/dt) of the Cr-Mo steels tested by pre-crack and the voltage (or resistance) variables were related into fracture parameter (Ct), crack growth coefficient (H), and an exponent (q) in the parts of Base, weld and HAZ. The fracture parameter (Ct) has various variables relating to the specimen and crack shape, applied stress, and creep strain curve. The H and q was inferred by OLS regression (ordinary least square method), and the H values were solved in statistics and probability assessment, which were attained fromPDF's distributions (probability density function). The HAZ part has the highest value of q by OLS regression and the widest distribution of H by PDF of WEIBULL, which means that the crack sensitivity of HAZ should be cautioned against the creep crack growth and failure.

Keywords

Acknowledgement

Supported by : 강릉원주대학교, 한국에너지 기술평가원(KETEP)

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