개량 9Cr-1Mo 강의 확률론적 크리프 균열 성장 거동

This paper deals with a probabilistic analysis for creep crack growth (CCG) behavior of Modified 9Cr-1Mo steel for next generation nuclear reactors. The CCG data were obtained by the CCG tests performed on 1/2" compact tension (CT) specimens under the applied load of 5000N at the identical temperature condition of 600℃. The CCG behavior was analyzed statistically by using the empirical equation between the CCG rate, da/dt and C* parameter. The B and q values were investigated by the least square fitting method for each specimen. The probabilistic distribution functions for the B and q were investigated by using the normal, log-normal and weibull distribution. It appeared that the results of the B and q constants followed Log-normal distribution well. From this result, it was identified that the CCG rate could be evaluated probabilistically for Modified 9Cr-1Mo steel.