확률적 방법에 의한 크리프 균열성장 계수의 분포 추정

• Published in: 대한금속·재료학회지, 48(9) Vol. 48; no. 9; pp. 791 - 797
• Main Authors: 이상호, Sang Ho Lee, 윤기봉, Kee Bong Yoon, 최병학, Byung Hak Choe, 민두식, Doo Sik Min, 안종석, Jong Seok Ahn, 이길재, Gil Jae Lee, 김선화, Sun Hwa Kim
• Format: Journal Article
• Language: Korean
• Published: 대한금속재료학회 20.09.2010; 대한금속·재료학회
• Subjects: creep; hot working; metals; probabilistic assessment; 재료공학
• ISSN: 1738-8228; 2288-8241

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 from PDF`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.