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Vol.47, No.5, 283 ~ 290, 2009
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| Title |
| Statistical Analysis for Creep Crack Growth Behavior of Modified 9Cr-1Mo Steel |
| 정익희 Ik Hee Jung , 김우곤 Woo Gon Kim , 윤송남 Song Nan Yin , 류우석 Woo Seog Ryu , 김선진 Seon Jin Kim |
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| Abstract |
| This paper dealt with a statistical analysis for evaluating the creep crack growth rate (CCGR) for Modified 9Cr-1Mo (ASTM Grade 91) steel. The CCGR data was obtained by the creep crack growth (CCG) tests conducted under various applied loads at 600℃. To obtain logically the B and q values used in the CCGR equation, three methods such as the least square fitting method (LSFM), the mean value method (MVM) and the probabilistic distribution method (PDM) were adopted and their CCGR lines were compared, respectively. In addition, a number of random variables were generated by using the Monte Carlo simulation (MCS), and the CCGR lines were predicted probabilistically. It was found that both the B and q coefficients followed a 2-parameter Weibull distribution well. In the case of the ranges of 10~90% for the probability variables, P(B, q), the CCGR lines were predicted. Fractographic study was conducted from the specimen after the CCG tests. (Received January 19, 2009) |
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| Key Words |
| creep crack growth rate, modified 9Cr-1Mo steel, monte-carlo simulation, probability |
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