Cr-Mo-V緞鋼のクリープキャビティ発生に対する統計的解析

抄録

In this study, an attempt to analyze the creep cavitation in Cr-Mo-V rotor steel based on probability theory or statistical mechanics was made. The following were obtained as the conclusions : a) Grain-boundary sliding which induces creep cavities may show an exponential distribution. b) "A" parameter data of Cr-Mo-V rotor steel may show a binomial distribution B(n' ; M', p), where n'=INT(A×M'+0.5), INT(x) is the maximum integer which is not larger than x, A=n/M, n is the number of damaged boundaries and M is the number of observed boundaries. The mean value of the distribution p is p={(t/tr)/(t/tr+k')}×exp{-C'/(t/tr)}, where t/tr is life fraction. The values of k', C' and M' shound be determined by the maximum likelihood method.